(CNN) More than 80 ISIS targets were attacked in the first hours of "Operation Euphrates Shield" early Wednesday, officials say, as Turkish armor and warplanes targeted a key ISIS-held town across its border with Syria.

Jarablus is one of the few towns in northern Syria that ISIS still controls and is a critical location for supplies, money and fighters coming into ISIS-held areas.

In recent months, much of Turkey's firepower has been directed at the Kurdish separatist PKK in southeastern Turkey and across the border in northern Iraq. It has also occasionally shelled ISIS positions in northern Syria, but its last-known airstrikes against ISIS were in November last year.

Why is Turkey doing this now?

Turkish authorities have been pressed into taking action against ISIS by the surge of suicide bombings in Turkey, as well as the terror group's use of safe houses and "informal" financial services on Turkish soil.

"Daesh should be completely cleansed from our borders, and we are ready to do that," Turkish Foreign Minister Mevlut Cavusoglu said Tuesday, using an Arabic acronym for ISIS.

Ankara may also have calculated that ISIS is especially vulnerable, after many of its remaining fighters fled Manbij, another key stronghold in Syria. The town was liberated by the Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab forces backed by the United States.

ISIS' lines of communication and resupply have now been disrupted and it's taken heavy losses across northern Syria in recent months.

But Turkey is anxious that ISIS' vulnerability could provide an opportunity for their "other" enemy in northern Syria -- the Kurdish YPG militia -- who have taken several villages near Jarablus recently.

What does Turkey want to achieve?

Turkey has several aims. One is to degrade ISIS in this area -- to push the threat it poses away from the Turkish border and make infiltration harder. Beyond that, Turkey wants this part of Syria to become part of its sphere of influence. If it can clear this area of ISIS, it plans to inject Syrian rebel groups that it supports, according to officials. Several hundred are currently massed on the border, according to the Syrian Observatory on Human Rights.

The advantage for Turkey in putting its "own" groups into this part of Syria is to stop the Kurdish advance in its tracks.

Ankara sees the YPG as a terrorist group indistinguishable from the PKK, which it battles on a daily basis in south-eastern Turkey. The Syrian Kurds have made no secret of their desire to expel ISIS and link the two regions of northern Syria they already control. They would then oversee much of Syria's border with Turkey.

Hence the words of Erdogan Wednesday: "Turkey is determined that Syria retains its territorial integrity and will take matters into its own hands if required to protect that unity."

How much is Turkey working with coalition partners?

"We are working together with the coalition regarding air support," Cavusoglu said Wednesday. In addition, it's likely that the US is providing intelligence and targeting data to Turkish forces using unmanned aerial vehicles from the Incirlik air base.

The US has long urged Turkey to become more involved in operations against ISIS in northern Syria, but relations have been strained by the crackdown following the coup attempt in Turkey last month and a surge of anti-US sentiment in Turkey.

Cooperating in a substantial effort to weaken ISIS -- just as Vice President Joe Biden arrives in Ankara -- is one way to overcome a troubled few weeks. Additionally, in light of the sudden rapprochement between Erdogan and President Vladimir Putin of Russia, the US wants to reinforce its partnership with Turkey.

The US is also sending a message to the Syrian Kurds, its most effective partner on the ground in this region: that American support is not a blank check and that they should not provoke the Turks by moving on Jarablus.

Will Turkey will get sucked in further?

If the aim of the operation is to expel ISIS from Jarablus and surrounding areas, it's unlikely to be achieved in days. Manbij took weeks to clear, despite a ground offensive and hundreds of US airstrikes. One problem is the risk of substantial civilian casualties. ISIS frequently uses civilians as human shields, preventing them from leaving urban areas, to make targeting more difficult.

Perhaps the greatest risk is that this incursion on the ground will spill over into conflict with Kurdish forces. But the Kurds will realize that with their light, outmoded weaponry, they are no match for Turkish tanks.

The US is likely encouraging the YPG -- to which it indirectly supplies weapons and training -- to stay out of this. Additionally, Syrian Kurdish sources say they believe Turkey would like nothing better than a pretext to go after the YPG.

But if the Kurds don't return to the eastern banks of the Euphrates -- Turkey's "red line" -- the operation against ISIS could evolve into something very different -- perhaps a broader operation that also focuses on the YPG.

Turkish public opinion is likely to support this operation, in light of recent attacks blamed on ISIS, so long as its scope and duration is defined.

But in Damascus, the Assad regime has bitterly criticized it as a "blatant breach to its sovereignty."

The Syrian Foreign Ministry said in a statement that "substituting (ISIS) with other terrorist organizations backed directly by Turkey" is not "fighting terrorism."</s>BEIRUT (AP) — Kurdish-led forces in northern Syria say Turkish airstrikes have hit their bases near Jarablus, a town seized by Turkey-backed rebels earlier this week.

The Jarablus Military Council says the airstrikes Saturday on their bases in Amarneh village marked an "unprecedented and dangerous escalation" and came after Turkish artillery shelled the positions the day before.

The Britain-based Syrian Observatory for Human Rights confirmed the airstrikes. Turkish officials could not immediately be reached for comment.

Turkish troops head to the Syrian border, in Karkamis, Turkey, Saturday, Aug. 27, 2016. Turkey on Wednesday sent tanks across the border to help Syrian rebels retake the key Islamic State-held town of Jarablus and to contain the expansion of Syria's Kurds in an area bordering Turkey .(AP Photo/Halit Onur Sandal)

The Jarablus Military Council is supported by the U.S.-backed and Kurdish-led Syria Democratic Forces. Turkey sent tanks across the border to help Syrian rebels capture Jarablus from the Islamic State group.

The incursion was partly aimed at containing Kurdish-led forces. Turkey says the Kurds must withdraw to the east of the nearby Euphrates River.

Turkish troops head to the Syrian border, in Karkamis, Turkey, Saturday, Aug. 27, 2016. Turkey on Wednesday sent tanks across the border to help Syrian rebels retake the key Islamic State-held town of Jarablus and to contain the expansion of Syria's Kurds in an area bordering Turkey. (AP Photo/Halit Onur Sandal)

Turkish tanks head to the Syrian border, in Karkamis, Turkey, Saturday, Aug. 27, 2016. Turkey on Wednesday sent tanks across the border to help Syrian rebels retake the key Islamic State-held town of Jarablus and to contain the expansion of Syria's Kurds in an area bordering Turkey. (AP Photo/Halit Onur Sandal)

Turkish ambulances return from the Syrian border, in Karkamis, Turkey, Saturday, Aug. 27, 2016. Turkey on Wednesday sent tanks across the border to help Syrian rebels retake the key Islamic State-held town of Jarablus and to contain the expansion of Syria's Kurds in an area bordering Turkey. (AP Photo/Halit Onur Sandal)

A Turkish army tank stationed overlooks the Syrian border, in Karkamis, Turkey, Saturday, Aug. 27, 2016. Turkey on Wednesday sent tanks across the border to help Syrian rebels retake the key Islamic State-held town of Jarablus and to contain the expansion of Syria's Kurds in an area bordering Turkey.(AP Photo/Halit Onur Sandal)</s>ANKARA (Reuters) - A car bomb at a police headquarters in Turkey’s largely Kurdish southeast killed at least eleven and wounded dozens on Thursday, officials said, two days after Turkey launched an incursion against Islamic State and Kurdish terrorists in Syria.

The state-run Anadolu news agency blamed the attack on the Kurdistan Workers Party (PKK), a terror group which has waged a three-decade insurgency for Kurdish autonomy and has been involved in almost daily clashes with security forces since a ceasefire collapsed more than a year ago.

There was no immediate claim of responsibility.

Large plumes of smoke billowed from the site in Cizre, located in Turkey’s Sirnak province bordering both Syria and Iraq, footage on CNN Turk showed. The broadcaster said a dozen ambulances and two helicopters had been sent to the scene.

Hospital sources initially told Reuters that nine people were killed and 64 wounded, but an official later said the toll was eight. It was not clear whether the casualties were civilians or police officers.

Photographs broadcast by private channel NTV showed a large three-floor building reduced to its concrete shell, with no walls or windows, and surrounded by grey rubble.

Turkish special forces, tanks and warplanes launched their first major incursion into Syria on Wednesday in support of Syrian rebels, in an operation President Tayyip Erdogan has said is aimed both at driving Islamic State away from the border area and preventing territorial gains by the Kurdish YPG militia.

Turkey views the YPG as an extension of the PKK, which is listed as a terrorist organization by Turkey, the United States and the European Union. More than 40,000 people, mostly Kurds, have died since the rebels took up arms in Turkey in 1984.

Turkish troops fired on YPG terrorists in northern Syria on Thursday. Also on Thursday, Interior Minister Efkan Ala accused the PKK of attacking a convoy carrying the country’s main opposition party leader, Kemal Kilicdaroglu.

The government has blamed the PKK for a series of terror attacks this month in the southeast. The group has claimed responsibility for at least one attack on a police station.</s>Turkey has suffered a deadly bomb blast and an unprecedented threat by a Syrian group, as it faces an escalation of its battle with Kurdish militants.

A truck bomb at a police headquarters in Cizre, in the Kurdish heartlands of the southeast, killed 11 people and wounded over 70 yesterday morning, in the latest indication that the Syrian conflict threatens to increase tensions within Turkey itself.

The blast came just hours after a Syrian Kurdish group called for retaliation against President Recep Tayyip Erdogan for sending Turkish forces into the country this week.

In an ostensibly anti-jihadi operation, Turkish troops, supplemented by Turkish-trained Syrian rebels, thwarted Kurdish plans for territorial expansion on Wednesday by taking over Jarablus, a Syrian town Isis had held since July 2013.

“Death to Erdogan and his mercenaries,” said a group known as the council of Aleppo, in a statement shared by the political arm of the Syrian Kurdish militias.

“We call on all the national revolutionary forces in Syria and to its north to face this invasion and to intervene immediately. Jarablus and north Syria will be a graveyard for the murderous invader Erdogan and his mercenaries.”

Control of Jarablus was a central goal of Kurdish militias in Syria, who had hoped to join two separate cantons they control in the north of the country and create a self-administered state along Turkey’s southern border.

The Syrian Kurdish militia is closely linked to the PKK, an outlawed group that has waged a conflict for more than 30 years to win self-rule for Turkey’s Kurdish minority, a battle in which tens of thousands of people have died.

Mujtaba Rahman, an analyst at the Eurasia Group, a consultancy, warned Ankara’s decision to intervene militarily in Syria was likely to exacerbate its long-running tensions with the PKK and could invite further attacks from Isis.

“This aggressive move will raise the stakes for Turkey’s involvement in Syria and introduces the risk of a further intervention to support rebel forces if they come under stress in the future,” he said.

“In the meantime, Turkey’s exposure to Syria will increase domestic security risks and is likely to provoke retaliatory attacks by Isis and the PKK in Turkey.”

The Turkey-backed rebels now intend to expand their corridor of influence, after the US pressured the Syrian Kurdish fighters to disperse from Manbij, a town they had helped liberate from Isis

“The next step is Al Bab,” said Mohammad al Shamali, a vice-president with the Turkmen Council, a group of fighters backed by Turkey, and rivals of both Isis and the Kurdish militias. He was referring to an Isis controlled city about 20km from Aleppo.</s>KARKAMIS, Turkey (Reuters) - Turkish troops fired on U.S.-backed Kurdish militia fighters in northern Syria on Thursday, highlighting the complications of an incursion meant to secure the border region against both Islamic State and Kurdish advances.

Syrian rebels backed by Turkish special forces, tanks and warplanes entered Jarablus, one of Islamic State’s last strongholds on the Turkish-Syrian border, on Wednesday.

But President Tayyip Erdogan and senior government officials have made clear the aim of “Operation Euphrates Shield” is as much about stopping the Kurdish YPG militia seizing territory and filling the void left by Islamic State as it is about eliminating the ultra-hardline Islamist group itself.

A Turkish security source said the army shelled the People’s Protection Units (YPG) south of Jarablus. Turkey’s state-run Anadolu agency described the action as warning shots.

Gunfire and explosions echoed around hills in the region on Thursday, a day after the incursion first began.

Some of the blasts were triggered as Turkish security forces cleared mines and booby traps left by retreating Islamic State militants, according to Nuh Kocaaslan, the mayor of Karkamis, which sits just across the border from Jarablus. He said three Turkish-backed Syrian rebels were killed but no Turkish troops.

Turkey, which has NATO’s second biggest armed forces, demanded that the YPG retreat to the east side of the Euphrates river within a week. The Kurdish militia had moved west of the river earlier this month as part of a U.S.-backed operation, now completed, to capture the city of Manbij from Islamic State.

Ankara views the YPG as a threat because of its close links to Kurdish militants waging a three-decade-old insurgency on its own soil. It has been alarmed by the YPG’s gains in northern Syria since the start of the Syrian civil war in 2011, fearing it could extend Kurdish control along Turkish borders and fuel the ambitions of Kurdish insurgents in Turkey.

Turkey’s stance has put it at odds with Washington, which sees the YPG as a rare reliable ally on the ground in Syria, where Washington is trying to defeat Islamic State while also opposing President Bashar al-Assad’s government in a complex, multi-sided, five-year-old civil war.

The Syrian Kurdish force is one of the most powerful militias in Syria and regarded as the backbone of the Syrian Democratic Forces (SDF), a U.S.-backed alliance formed last October to fight Islamic State.

Turkish Defense Minister Fikri Isik said the Kurdish PYD party, the political arm of the YPG, wanted to unite Kurdish-controlled cantons east of Jarablus with those further west. “We cannot let this happen,” he said.

“Islamic State should be completely cleansed, this is an absolute must. But it’s not enough for us ... The PYD and the YPG militia should not replace Islamic State there,” Isik told Turkish broadcaster NTV.

EUPHRATES

U.S. Secretary of State John Kerry told Turkish Foreign Minister Mevlut Cavusoglu by phone on Thursday that YPG fighters were retreating to the east side of the Euphrates, as Turkey has demanded, foreign ministry sources in Ankara said.

A spokesman for the U.S.-led coalition against Islamic State said the SDF had withdrawn across the Euphrates, doing so “to prepare for the eventual liberation” of Raqqa, the radical group’s stronghold which lies further east.

Turkish army tanks make their way towards the Syrian border town of Jarablus, Syria August 24, 2016. Revolutionary Forces of Syria Media Office/Handout via REUTERS

Isik said the retreat was not yet complete and Washington had given assurances that this would happen in the next week.

“If the PYD does not retreat to east of the Euphrates, we have the right to do everything about it,” the minister said.

The offensive is Turkey’s first major military operation since a failed July 15 coup shook confidence in its ability to step up the fight against Islamic State. It came four days after a suicide bomber suspected of links to the group killed 54 people at a wedding in the southeastern city of Gaziantep.

U.S. Vice President Joe Biden, who met Erdogan during a trip to Turkey on Wednesday, said Turkey was ready to stay in Syria for as long as it takes to destroy the radical Islamist group.

“I think there has been a gradual mind shift ... in Turkey, with the realization that ISIL is an existential threat to Turkey,” he told reporters during a visit to Sweden, using an acronym for the militant group.

A Turkish official said the ground incursion had been in the works for more than two years but had been delayed by U.S. reservations, resistance from some Turkish commanders, and a stand-off with Russia which had made air cover impossible.

Turkey had made the case more strongly to Washington over the past few months, had patched up relations with Russia, and had removed some of the Turkish commanders from their posts after finding they were involved in the coup attempt, paving the way for the operation to go ahead, the official said.

The incursion comes at a testing time for Turkish-U.S. relations. Erdogan wants the United States to extradite Fethullah Gulen, a Turkish cleric who has lived in self-imposed exile in Pennsylvania for 17 years and whose religious movement Turkey blames for staging last month’s failed coup.

Washington says it needs clear evidence of Gulen’s involvement and that it is a matter for the courts, a position that has sparked an outpouring of anti-Americanism from Turkey’s pro-government media. Gulen denies any role in the coup attempt.

REBELS ADVANCE

The sound of gunfire, audible from a hill on the Turkish side of the border overlooking Jarablus, rang out on Thursday and black smoke rose over the town. War planes flew overhead.

A senior Turkish official said there were now more than 20 Turkish tanks inside Syria and that additional tanks and construction machinery would be sent in as required. A Reuters witness saw at least nine tanks enter on Thursday, and 10 more were waiting outside a military outpost on the Turkish side.

“We need construction machinery to open up roads ... and we may need more in the days ahead. We also have armored personnel carriers that could be used on the Syrian side. We may put them into service as needed,” the official said.

Erdogan said on Wednesday that Islamic State had been driven out of Jarablus and that it was now controlled by Turkish-backed Syrian rebels, who are largely Arab and Turkmen.

“The myth that the YPG is the only effective force fighting Islamic State has collapsed,” Erdogan’s spokesman Ibrahim Kalin wrote on Twitter, reflecting Turkish frustration at how closely Washington has been working with the Kurdish militia.

Slideshow (13 Images)

Saleh Muslim, head of the Kurdish PYD, said on Wednesday that Turkey was entering a “quagmire” in Syria and faced defeat there like Islamic State. Redur Xelil, spokesman for the YPG, said the intervention was a “blatant aggression in Syrian internal affairs”.

After seizing Jarablus, the Turkish-backed rebels have advanced up to 10 km (6 miles) south of the border town, rebel sources and a group monitoring the war said.

But the Syrian Observatory for Human Rights also said Kurdish-backed forces opposed by Ankara had gained up to 8 km of ground northwards, apparently seeking to pre-empt advances by the rebels.</s>(CNN) More than 80 ISIS targets were attacked in the first hours of "Operation Euphrates Shield" early Wednesday, officials say, as Turkish armor and warplanes targeted a key ISIS-held town across its border with Syria.

Jarablus is one of the few towns in northern Syria that ISIS still controls and is a critical location for supplies, money and fighters coming into ISIS-held areas.

In recent months, much of Turkey's firepower has been directed at the Kurdish separatist PKK in southeastern Turkey and across the border in northern Iraq. It has also occasionally shelled ISIS positions in northern Syria, but its last-known airstrikes against ISIS were in November last year.

Why is Turkey doing this now?

Turkish authorities have been pressed into taking action against ISIS by the surge of suicide bombings in Turkey, as well as the terror group's use of safe houses and "informal" financial services on Turkish soil.

"Daesh should be completely cleansed from our borders, and we are ready to do that," Turkish Foreign Minister Mevlut Cavusoglu said Tuesday, using an Arabic acronym for ISIS.

Ankara may also have calculated that ISIS is especially vulnerable, after many of its remaining fighters fled Manbij, another key stronghold in Syria. The town was liberated by the Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab forces backed by the United States.

ISIS' lines of communication and resupply have now been disrupted and it's taken heavy losses across northern Syria in recent months.

But Turkey is anxious that ISIS' vulnerability could provide an opportunity for their "other" enemy in northern Syria -- the Kurdish YPG militia -- who have taken several villages near Jarablus recently.

What does Turkey want to achieve?

Turkey has several aims. One is to degrade ISIS in this area -- to push the threat it poses away from the Turkish border and make infiltration harder. Beyond that, Turkey wants this part of Syria to become part of its sphere of influence. If it can clear this area of ISIS, it plans to inject Syrian rebel groups that it supports, according to officials. Several hundred are currently massed on the border, according to the Syrian Observatory on Human Rights.

The advantage for Turkey in putting its "own" groups into this part of Syria is to stop the Kurdish advance in its tracks.

Ankara sees the YPG as a terrorist group indistinguishable from the PKK, which it battles on a daily basis in south-eastern Turkey. The Syrian Kurds have made no secret of their desire to expel ISIS and link the two regions of northern Syria they already control. They would then oversee much of Syria's border with Turkey.

Hence the words of Erdogan Wednesday: "Turkey is determined that Syria retains its territorial integrity and will take matters into its own hands if required to protect that unity."

How much is Turkey working with coalition partners?

"We are working together with the coalition regarding air support," Cavusoglu said Wednesday. In addition, it's likely that the US is providing intelligence and targeting data to Turkish forces using unmanned aerial vehicles from the Incirlik air base.

The US has long urged Turkey to become more involved in operations against ISIS in northern Syria, but relations have been strained by the crackdown following the coup attempt in Turkey last month and a surge of anti-US sentiment in Turkey.

Cooperating in a substantial effort to weaken ISIS -- just as Vice President Joe Biden arrives in Ankara -- is one way to overcome a troubled few weeks. Additionally, in light of the sudden rapprochement between Erdogan and President Vladimir Putin of Russia, the US wants to reinforce its partnership with Turkey.

The US is also sending a message to the Syrian Kurds, its most effective partner on the ground in this region: that American support is not a blank check and that they should not provoke the Turks by moving on Jarablus.

Will Turkey will get sucked in further?

If the aim of the operation is to expel ISIS from Jarablus and surrounding areas, it's unlikely to be achieved in days. Manbij took weeks to clear, despite a ground offensive and hundreds of US airstrikes. One problem is the risk of substantial civilian casualties. ISIS frequently uses civilians as human shields, preventing them from leaving urban areas, to make targeting more difficult.

Perhaps the greatest risk is that this incursion on the ground will spill over into conflict with Kurdish forces. But the Kurds will realize that with their light, outmoded weaponry, they are no match for Turkish tanks.

The US is likely encouraging the YPG -- to which it indirectly supplies weapons and training -- to stay out of this. Additionally, Syrian Kurdish sources say they believe Turkey would like nothing better than a pretext to go after the YPG.

But if the Kurds don't return to the eastern banks of the Euphrates -- Turkey's "red line" -- the operation against ISIS could evolve into something very different -- perhaps a broader operation that also focuses on the YPG.

Turkish public opinion is likely to support this operation, in light of recent attacks blamed on ISIS, so long as its scope and duration is defined.

But in Damascus, the Assad regime has bitterly criticized it as a "blatant breach to its sovereignty."

The Syrian Foreign Ministry said in a statement that "substituting (ISIS) with other terrorist organizations backed directly by Turkey" is not "fighting terrorism."</s>Kurdish-aligned group in north Syria says targeted by Turkish warplanes

KARKAMIS, Turkey, Aug 27 (Reuters) - A group allied to Kurdish-backed Syrian Democratic Forces (SDF) said it was bombarded by Turkish warplanes on Saturday, after Turkey's military launched an incursion this week into northern Syria against both Islamic State and Kurdish forces.

Turkish officials had no immediate comment on the report which, if confirmed, would signal Turkey's action against Kurdish-aligned forces was being ratcheted up a notch.

The Jarablus Military Council, a group that is part of the SDF, said jets hit positions near the strategic town of Jarablus. It reported civilian casualties and called the strike "a dangerous escalation".

Early on Saturday, a Reuters witness in Karkamis, a Turkish town on the other side of the border from Syria's Jarablus, saw warplanes flying from Turkish air space into Syria and then heard several explosions. The identity of the planes was not clear.

Syrian rebels backed by Turkish special forces, tanks and warplanes entered Jarablus this week, seizing the frontier town that had been an Islamic State stronghold. The rebel force backed by Turkey were largely Arab and Turkmen.

The Turkish campaign pre-empted action by Kurdish-backed forces which had sought to get to Jarablus first.

But Turkish President Tayyip Erdogan and other senior officials has made clear that the incursion is as much about pushing away Islamic State as it is about preventing Kurdish forces filling the void left as the Islamists withdraw.

Turkey wants to stop Kurdish forces gaining control of a continuous stretch of territory along its southern border, which Ankara fears they could use to support the Kurdish militant group PKK that is fighting an insurgency on Turkish soil.

The Jarablus Military Council said the village of al-Amarna, which lies a few km south of Jarablus, was hit. In response to the Turkish strike, it said: "If they do not attack our forces, then we will keep the border strip secure."

The newly formed Jarablus Military Council has said it is made up by people from the area with the aim of capturing the town and the surrounding area from Islamic State militants. However, the Turkish-backed rebels seized Jarablus first.

The Jarablus Military Council has aligned itself with the SDF, which encompasses several militias including Arabs and the Kurdish YPG group.

The SDF is also backed by the United States, putting Ankara at odds with its NATO ally Washington in its engagement in Syria, where the multi-faceted conflict has raged for five years, creating complex rivalries and alliances.

On Thursday, a day after Turkey began its cross-border offensive, Turkish troops fired on U.S.-backed YPG forces, which is part of the SDF. Turkey's state news agency described that salvo as warning shots. The use of Turkish warplanes against an SDF-aligned group would point to tougher action.

A Reuters witness in Karkamis heard blasts and smoke rising from the nearby Syrian village of Kivircik.

Several militias under the SDF banner pledged support to Jarablus Military Council after it reported the Turkish bombing.

The Northern Sun Battalion, an SDF faction, said in a statement it was heading to "Jarablus fronts" to help the council against "threats made by factions belonging to Turkey".

Tension has mounted in the past year between the Kurdish YPG force and its allies on one hand and Turkish-backed rebel groups fighting President Bashar al-Assad on the other, in the Aleppo region. The two sides have clashed on several occasions. (Additional reporting by Ece Toksabey and Orhan Coskun in Ankara; writing by Edmund Blair; editing by Mark Heinrich)</s>KARKAMIS, Turkey — Turkey sent more tanks into northern Syria on Thursday and demanded Kurdish militia fighters retreat within a week as it seeks to secure the border region and drive back the Daesh terror group with its first major incursion into its neighbour.

Syrian rebels backed by Turkish special forces, tanks and warplanes on Wednesday entered Jarablus, one of Daesh’s last strongholds on the Turkish-Syrian border. Gunfire and explosions echoed around hills in the region on Thursday.

Some of the blasts were triggered as Turkish security forces cleared mines and booby traps left by retreating Daesh militants, according to Nuh Kocaaslan, the mayor of Karkamis, which sits just across the border from Jarablus.

Three Syrian rebels were killed during the operation to take Jarablus, one of them when he opened the door of a house rigged with explosives, Kocaaslan told reporters. There were no casualties among the Turkish troops.

President Recep Tayyip Erdogan and senior government officials have made clear the aim of “Operation Euphrates Shield” is as much about stopping the Kurdish YPG militia seizing territory and filling the void left by Daesh as about eliminating the radical group itself.

Turkey, which has NATO’s second biggest armed forces, demanded that the YPG retreat to the east side of the Euphrates River within a week. The Kurdish militia had moved west of the river earlier this month as part of a US-backed operation, now completed, to capture the city of Manbij from Daesh.

Ankara views the YPG as a threat because of its close links to Kurdish militants waging a three-decade-old insurgency on its own soil. It has been alarmed by the YPG’s gains in northern Syria since the start of the Syrian civil war in 2011, fearing it could extend Kurdish control along Turkish borders and fuel the ambitions of Kurdish insurgents in Turkey.

Turkey’s stance has put it at odds with Washington, which sees the YPG as a rare reliable ally on the ground in Syria, where Washington is trying to defeat Daesh while also opposing President Bashar Assad’s government in a complex, multi-sided five-year-old civil war.

The Syrian Kurdish force is one of the most powerful militias in Syria and regarded as the backbone of the Syrian Democratic Forces (SDF), a US-backed alliance formed last October to fight Daesh.

Turkish Defence Minister Fikri Isik said preventing the Kurdish PYD Party — the political arm of the YPG — from uniting Kurdish cantons east of Jarablus with those further west was a priority.

“Daesh should be completely cleansed, this is an absolute must. But it’s not enough for us.... The PYD and the YPG militia should not replace Islamic State [Daesh] there,” Isik told Turkish broadcaster NTV.

“The PYD’s biggest dream is to unify the western and eastern cantons. We cannot let this happen,” he said.

US Secretary of State John Kerry told Turkish Foreign Minister Mevlut Cavusoglu by phone on Thursday that YPG fighters were retreating to the east side of the Euphrates, as Turkey has demanded, foreign ministry sources in Ankara said.

A spokesman for the US-led coalition against Daesh also said the SDF had withdrawn across the Euphrates, doing so “to prepare for the eventual liberation” of Raqqa, the radical group’s stronghold in northern Syria, which is to the east.

Isik said the retreat was not yet complete and Washington had given assurances that this would happen in the next week.

“We are closely following this... If the PYD does not retreat to east of the Euphrates, we have the right to do everything about it,” he said.

The offensive is Turkey’s first major military operation since a failed July 15 coup shook confidence in its ability to step up the fight against Daesh. It came four days after a suicide bomber suspected of links to the group killed 54 people at a wedding in the southeastern city of Gaziantep.

US Vice President Joe Biden, who met Erdogan during a trip to Turkey on Wednesday, said Turkey was ready to stay in Syria for as long as it takes to destroy the radical Islamist group.

“I think there has been a gradual mind shift... in Turkey, with the realisation that ISIL [Daesh] is an existential threat to Turkey,” he told reporters during a visit to Sweden.

A Turkish official said the ground incursion had been in the works for more than two years but had been delayed by US reservations, resistance from some Turkish commanders, and a stand-off with Russia which had made air cover impossible.

Turkey had made the case more strongly to Washington over the past few months, had patched up relations with Russia, and had removed some of the Turkish commanders from their posts after finding they were involved in the coup attempt, paving the way for the operation to go ahead, the official said.

The incursion comes at a testing time for Turkish-US relations. Erdogan wants the United States to extradite Fethullah Gulen, a Turkish cleric who has lived in self-imposed exile in Pennsylvania for 17 years and whose religious movement Turkey blames for staging last month’s failed coup.

Washington says it needs clear evidence of Gulen’s involvement and that it is a matter for the courts, a position that has sparked an outpouring of anti-Americanism from Turkey’s pro-government media. Gulen denies any role in the coup attempt.

The sound of gunfire, audible from a hill on the Turkish side of the border overlooking Jarablus, rang out early on Thursday and a plume of black smoke rose over the town. Warplanes flew overhead.

A senior Turkish official said there were now more than 20 Turkish tanks inside Syria and that additional tanks and construction machinery would be sent in as required. A Reuters witness saw at least nine tanks enter on Thursday, and 10 more were waiting outside a military outpost on the Turkish side.

“We need construction machinery to open up roads... and we may need more in the days ahead. We also have armoured personnel carriers that could be used on the Syrian side. We may put them into service as needed,” the official said.

Erdogan said on Wednesday that Daesh had been driven out of Jarablus and that it was now controlled by Turkish-backed Syrian rebels, who are largely Arab and Turkmen.

“The myth that the YPG is the only effective force fighting Daesh has collapsed,” Erdogan’s spokesman Ibrahim Kalin wrote on Twitter, reflecting Turkish frustration at how closely Washington has been working with the Kurdish militia.

Saleh Muslim, head of the Kurdish PYD, said on Wednesday that Turkey was entering a “quagmire” in Syria and faced defeat there like Daesh. Redur Xelil, spokesman for the YPG, said the intervention was a “blatant aggression in Syrian internal affairs”.

After seizing Jarablus, the Turkish-backed rebels have advanced up to 10km south of the border town, rebel sources and a group monitoring the war said.

But the Syrian Observatory for Human Rights also said Kurdish-backed forces opposed by Ankara had gained up to 8km of ground northwards, apparently seeking to pre-empt advances by the rebels.</s>Turkish Prime Minister Binali Yidirim on Friday denounced as a "bare-faced lie" suggestions in Western media that Ankara's military operation in Syria was singling out Kurdish people rather than jihadists.

"They either know nothing about the world, or else their job is to report a bare-faced lie," Yildirim snarled when asked to comment on claims the operation was not targeting Islamic State (IS) jihadists but Kurds.

He had been asked to respond to an article in German weekly Der Spiegel -- which frequently riles the Turkish authorities -- with the headline "Turkey's Syria operation -- IS is the pretext, the Kurds the target".

Yildirim said: "Our soldiers' mission is to ensure our border security and the life and property of our citizens. The news apart from that is just a lie."

"You tell lies that Turkey is weak in the fight against ISIS (IS) but when we save innocent lives from ISIS you go and write this," he fumed.

Ankara has said it will act in the operation against the Kurdish Democratic Union Party (PYD) and its People's Protection Units (YPG) militia who it accuses of seeking to carve out an autonomous region in northern Syria.

Turkey regards the organisations as terror groups who represent neither the Kurdish nor the Syrian people. The YPG are allies of the United States in the fight against IS but Ankara argues this is a dangerous error.</s>Russia says a solution to Syria's 5 1/2-year-long war may be getting closer after relations improved with Turkey, a major backer of rebel groups fighting the regime of President Bashar al-Assad.

"It's a very important moment," Maria Zakharova, the Foreign Ministry's spokeswoman, said in an interview in Moscow Thursday. Turkey "is showing its interest in both the military and political sphere" in resolving the Syrian conflict and "when there's a constructive dialogue then of course it always helps the situation to develop in a positive way. It's a step in the right direction."

Russia welcomes contact between Turkey and Iran as a "constructive contribution" to resolving the Syrian crisis, Zakharova said. "If we communicate with Turkey and Iran, why shouldn't Turkey and Iran talk to each other? Many in Washington don't like it, but it's an important element" in diplomatic discussions, she said.

The thawing of relations between Russia and Turkey is taking place as the government in Ankara carries out its biggest military operation in Syria. Turkey is seeking to drive Islamic State militants away from its border and deter advances by Kurds allied with Turkish separatists. Jets pounded Islamic State positions and tanks crossed the border this week, allowing the Turkish-backed Free Syrian Army to gain control of the strategic town of Jarablus, state-run Anadolu news service reported Wednesday.

A softening in Turkey's insistence on Assad's departure in any settlement of the war has narrowed differences with Russia, which has conducted air strikes in support of the Syrian leader since September.

Turkey has also reached out to Iran, Assad's other main supporter. Iranian Foreign Minister Mohammad Javad Zarif visited Ankara a few days after Turkish leader Recep Tayyip Erdogan held talks with President Vladimir Putin in St. Petersburg this month to repair relations that had been plunged into crisis when Turkey shot down a Russian military jet near the border with Syria in November.

Russia "sees potential for it and Turkey and Iran to reach a compromise," said Irina Zvagelskaya, a senior fellow at the Russian Academy of Sciences' Institute of Oriental Studies. "For Turkey, the only red line is the Kurds."

Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry will discuss efforts to coordinate actions against terrorists in Syria when they meet in Geneva on Friday, Zakharova said.

Russia and the U.S. have tried unsuccessfully so far to reach agreement on synchronizing air strikes against militants in Syria, a move that could revive efforts to end a war in which more than 280,000 people have been killed and millions more have fled to neighboring countries and Europe.

"If we consider the Syrian settlement to be important then this is key -- it's a cornerstone of what is happening there" because "we need to destroy the terrorists," Zakharova said before leaving with Lavrov for Geneva. The U.S. targets "terrorists where there are no opposition members shielding them. Where they are being shielded under Washington's direction we have a problem."

A "terrorist center remains" in these areas of Syria and "no one can deal with it because so-called moderate opposition groups are there," Zakharova said.

The Turkish offensive aims to push Islamic State deeper into Syria and create a buffer zone against the Syrian Kurds if they attempt to move northward toward the border. It has produced a rare degree of unity between the U.S., Russia and Turkey, with a Russian Foreign Ministry official calling the action "timely," while the U.S. extended its cooperation.

The U.S.-backed Syrian Kurds have been seeking to link enclaves they control by seizing major villages and towns from Islamic State along the border with Turkey. That alarmed Ankara, which fears the campaign will encourage restive Kurds in its east.

Russia may have agreed not to object to a limited Turkish incursion into Syria in return for Turkey being more cooperative on a political settlement with Assad, according to Dmitri Trenin, head of the Carnegie Moscow Center.

Turkish Prime Minister Binali Yildirim said last week that a transition with Assad still in power is possible and he called the confrontation over the downed Russian warplane an "unnecessary crisis." Yildirim on Wednesday said Turkey will increase cooperation with Iran on Syria and fighting Turkish separatist Kurds.

Demands for Assad to step down are unacceptable and "there can't be any preconditions in fighting against terrorism," Zakharova said. The presidency "is an important key to maintaining a strong fight against terrorists on the ground" in Syria, she said.
Turkey sends more tanks into northern Syria to continue its offensive against Islamic State of Iraq and the Levant and Kurdish People's Protection Units (YPG).