BEIRUT -- The U.S. sent aircraft to strike Syrian regime vehicles on Thursday that violated a deconfliction zone set up around al-Tanf, an army base where special forces are training Syrian militias, CBS News national security correspondent David Martin reports.

American officials and Syrian activists said the strike hit the pro-Syrian government forces as they were setting up fighting positions in a protected area in the desert near the border with Jordan. A bulldozer and a tank were hit, although it was unclear if it struck the Syrian army or just militias allied with the government.

The region around al-Tanf, where the borders of Jordan, Syria and Iraq meet, has been considered a deconfliction zone, under an agreement between the U.S. and Russia.

The Syrian regime has violated the zone two times in the past few days, Martin reports.

In one incident, 27 regime vehicles drove within 18 miles of al-Tanf, which breached the 34 mile radius of the army convoy. U.S. aircraft attempted to buzz the regime, but when the convoy didn't turn around, they conducted a strike against some of the vehicles.

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In the second incident, an unarmed Syrian SU-22 fighter-bomber entered the deconfliction zone and was intercepted by a pair of F-22 fighter aircraft.

Speaking to reporters, Defense Secretary Jim Mattis said the U.S. will defend its troops in case of "aggressive" steps against them. He was asked if the airstrike increases the U.S. role in the Syrian war.

"We are not increasing our role in the Syrian civil war, but we will defend our troops," Mattis said. "And that is a coalition element made up of more than just U.S. troops, and so we will defend ourselves (if) people take aggressive steps against us."

The U.S. strike marks a new approach in what has become an intensely crowded and complicated war zone. Thursday's strike was the coalition's first on pro-Assad forces in the battlefield. The coalition had so far kept its military operations focused on Islamic State militants and al-Qaida-linked groups.

Operation Inherent Resolve, the U.S.-led campaign against the Islamic State of Iraq and Syria (ISIS), said in a statement that "the coalition struck pro-regime forces that were advancing well inside an established de-confliction zone" and "posed a threat to U.S. and partner forces" at al-Tanf.

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It said the action was taken after "apparent Russian attempts to dissuade Syrian pro-regime movement" toward al-Tanf were unsuccessful, and after a "coalition aircraft show of force" and warning shots.

"The agreed upon de-confliction zone agreement remains in effect," the statement said.

It remains unclear why the Syrians violated the zone. Martin reports that Syrian forces are pushing eastward toward the Euphrates River Valley, which hints to the idea that the regime may have been doing reconnaissance on their flank.

The base was attacked by ISIS in April. Last summer, Syrian fighters trained by the U.S. who operated out of al-Tanf were bombed by Russian jets.

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ISIS attacks Syrian state-held areas

ISIS attacked several government-held villages in central Syria on Thursday, capturing at least one of them in violence that left 52 people dead, including 11 women and 17 children.

Some of the women were beheaded and others had their limbs amputated. Children's bodies were mostly dismembered due to the fact they were beaten with heavy objects such as bricks or stones. Most of the men died from shelling or heavy machine gun fire.

Hospital officials say 120 people were wounded in the attack.

The attack in the central Hama province targeted villages where most residents belong to the Ismaili branch of Shiite Islam, raising fears the extremists might massacre them, as they have in other minority communities in Syria and Iraq.

The villages are located near the town of Salamiyeh and the highway that links the capital, Damascus, to the northern city of Aleppo, but state media said traffic was not affected.

The attacks come as goverment forces are on the offensive against the extremists in other parts of Syria, mostly in the northern province of Aleppo and the central Homs region and to the east.

U.S.-backed and Kurdish-led forces are meanwhile marching toward the extremists' de-facto capital of Raqqa, in northern Syria.</s>The U.S. bombed a convoy of pro-Assad fighters Thursday as they advanced on U.S. “partner forces,” according to the coalition’s official Twitter account.

Another tweet added that the strike came only after several attempts to warn the convoy from advancing any further.

The al-Tanf area referenced is home to a base where U.S. special forces train anti-ISIS fighters. It’s surrounded by a deconfliction zone. The pro-Assad forces got too close to that zone, USA Today reports, adding that the “airstrike targeted a tank and two earth movers that were building fighting positions within the defensive zone.”

U.S. military is not yet certain if those bombed were Syrian army or pro-Assad militia, USA Today notes. BuzzFeed says the convoy included “regime-allied militia mixed with Syrian government forces.” And a leader from a “Pentagon-backed rebel group” told Reuters that the forces were made up of the “Syrian army and Iranians.”

A strike on pro-Assad forces, be they militia troops or members of the Syrian army, marks a turn from the reason the U.S. is in Syria — to fight ISIS. This is only the second time the U.S. has bombed pro-Assad targets after last month’s strikes on an airfield in retaliation for a chemical attack.

Fighting Assad and ISIS at the same time is not only “madness and idiocy,” as Trump said last year, it’s potentially illegal given the lack of Congressional authorization to strike regime targets. That’s a point one Democratic lawmaker is already making.</s>The Pentagon’s account of its Thursday-night air strike on pro-Assad militia forces in Syria concealed the real story of a race to the Syrian-Iraqi border by armed groups working for both the Americans and the Syrian regime. Even the targets listed by the US appear to have been wrong. Indeed, what was described by the Americans as a minor action was part of a far more important struggle between the US and the Syrian regime for control of the south-eastern frontier of Syria – a vital supply line for Iran to maintain its forces in Syria.

According to the Syrians, the US destroyed not one but four T-62 tanks and a Shilka ZSU-23-4 Soviet-made radar-guided anti-aircraft vehicle manned by both Shia Iraqi militiamen loyal to Damascus and a unit of armed Iranians who were travelling in pick-up trucks to establish positions – on the instructions of the Syrian army – in the desert west of al-Tanf. Their intention – to set up strongpoints in the vast and largely empty land in advance of the American-trained forces – was an attempt by the Syrian government to keep open the route between Iraq and Syria now that the ISIS-held Syrian city of Raqqa far to the north has been almost surrounded by largely Kurdish fighters loyal to Washington.

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Six of the pro-Syrian militiamen were killed in the American air strike and 25 wounded – it is unclear whether the casualties were Iraqi or Iranian – but forces under the command of the Syrian army intend to continue their reconnaissance missions towards al-Tanf. Anti-aircraft gunners aboard one of the pick-up trucks accompanying the pro-Syrian units that were attacked, opened fire on the US jets and, according to the Syrians, forced the American aircraft to fly higher.

At this point, Syrian air defence units north-east of Damascus prepared to fire Soviet-made S-200 Angara ground-to-air missiles (an older version of the S-300 which the Russians have since delivered to the Syrian military) at the Americans – but the US jets had by then left Syrian airspace. One of the five T-62 tanks attacked by the Americans was undamaged.

Nonetheless, the brief action in the Syrian desert was of great importance. The Syrians were obviously trying to test America’s resolve to move its anti-Assad militia forces deeper into the south-east of the country – and the US was prepared, albeit on a small scale, to show that it was prepared to press on. But the Syrian-Iraqi frontier town of al-Tanf may turn out to be a key strategic point in the struggle of the Assad government to regain its national territory and keep open its border to Iraq and, by extension, to Iran. It lies only 30 miles from Iraq – but because the Jordanian-Syrian-Iraqi borders join immediately to the south – al-Tanf also lies the same distance from Jordan – where the American-trained militia are based.

Shape Created with Sketch. In pictures: US missile strike against Syria Show all 7 left Created with Sketch. right Created with Sketch. Shape Created with Sketch. In pictures: US missile strike against Syria 1/7 The guided-missile destroyer USS Porter (DDG 78) launches a tomahawk land attack missile in the Mediterranean Sea AP 2/7 The United States military launched at least 50 tomahawk cruise missiles at al-Shayrat military airfield near Homs, Syria, in response to the Syrian military's alleged use of chemical weapons in an airstrike in a rebel held area in Idlib province EPA 3/7 Shayrat airfield in Syria Getty Images 4/7 US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters 5/7 US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters 6/7 President Donald Trump speaks at Mar-a-Lago in Palm Beach, Fla., after the US fired a barrage of cruise missiles into Syria in retaliation for this week's gruesome chemical weapons attack against civilians AP 7/7 Syria's President Bashar al-Assad Reuters 1/7 The guided-missile destroyer USS Porter (DDG 78) launches a tomahawk land attack missile in the Mediterranean Sea AP 2/7 The United States military launched at least 50 tomahawk cruise missiles at al-Shayrat military airfield near Homs, Syria, in response to the Syrian military's alleged use of chemical weapons in an airstrike in a rebel held area in Idlib province EPA 3/7 Shayrat airfield in Syria Getty Images 4/7 US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters 5/7 US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters 6/7 President Donald Trump speaks at Mar-a-Lago in Palm Beach, Fla., after the US fired a barrage of cruise missiles into Syria in retaliation for this week's gruesome chemical weapons attack against civilians AP 7/7 Syria's President Bashar al-Assad Reuters

Although US jets were involved in Thursday’s air strikes, the forces on the ground comprised largely proxy fighters – belonging to both the American-trained ‘rebel’ opposition and to the Syrian military. If US personnel were accompanying the ‘rebel’ forces, then they were lucky that neither the Russians nor Syrian Army personnel were present on the other side. For the Pentagon to suggest that this was a sideshow to Washington’s battle against Isis was to stretch the truth beyond credibility in the Middle East. Cutting Syria off from Iraq – and thus from Iran – appears to be a far more immediate operational aim of US forces in Syria than the elimination of the Sunni “Caliphate” cult that Washington claims to be its principal enemy in the Middle East.</s>The U.S. bombed a convoy of pro-Assad fighters Thursday as they advanced on U.S. “partner forces,” according to the coalition’s official Twitter account.

Another tweet added that the strike came only after several attempts to warn the convoy from advancing any further.

The al-Tanf area referenced is home to a base where U.S. special forces train anti-ISIS fighters. It’s surrounded by a deconfliction zone. The pro-Assad forces got too close to that zone, USA Today reports, adding that the “airstrike targeted a tank and two earth movers that were building fighting positions within the defensive zone.”

U.S. military is not yet certain if those bombed were Syrian army or pro-Assad militia, USA Today notes. BuzzFeed says the convoy included “regime-allied militia mixed with Syrian government forces.” And a leader from a “Pentagon-backed rebel group” told Reuters that the forces were made up of the “Syrian army and Iranians.”

A strike on pro-Assad forces, be they militia troops or members of the Syrian army, marks a turn from the reason the U.S. is in Syria — to fight ISIS. This is only the second time the U.S. has bombed pro-Assad targets after last month’s strikes on an airfield in retaliation for a chemical attack.

Fighting Assad and ISIS at the same time is not only “madness and idiocy,” as Trump said last year, it’s potentially illegal given the lack of Congressional authorization to strike regime targets. That’s a point one Democratic lawmaker is already making.</s>Pro-Syrian government forces hit by U.S.-led coalition airstrikes in an established deconfliction zone inside Syria were directed by Iran, U.S. Secretary of Defense Jim Mattis said Friday.

Mattis told reporters at the Pentagon the strikes were conducted in "self-defense" and were "necessitated by offensive movement with offensive capability of what we believe were Iranian-directed forces." He added that it was unclear whether Iranians were on the ground with the forces.

U.S. Central Command spokesman Major Josh Jacques said in an interview with VOA on Thursday that pro-Syrian government forces set up a convoy northwest of the al-Tanf army base — where U.S.-led coalition forces are training Syrian militias fighting Islamic State — with Syrian tanks, bulldozers, armored vehicles, artillery vehicles and technical vehicles, and began creating fighting positions for their tanks.

Coalition strikes destroyed one of the tanks, two front-end loaders, another piece of construction equipment and a tactical vehicle, according to a U.S. Central Command strike release.

Officials say some of the pro-Syrian government forces are still violating the deconfliction zone set up around the al-Tanf base. The zone has been established as the area within a 55-kilometer radius from the base.

"We're calling on them to withdraw from the deconfliction zone," Jacques told VOA.

Over several hours, the coalition flew aircraft through the airspace and fired missiles into the ground as "warning shots" near the pro-Syrian forces, but they continued building their positions, Jacques said.

The coalition also used a deconfliction hotline established between the U.S. and Russia to see if the Russians could get them to leave the area, but several apparent Russian attempts led to no change from the forces.

"It looks like the Russians tried to dissuade them," Mattis said Friday.

"After that, we couldn't do much else," Jacques said. "They had every opportunity to leave the area."

Syria has condemned the deadly coalition attack and said airstrikes near the border with Jordan are hampering efforts by the Syrian army and its allies to fight Islamic State.

Syrian rebels hailed the coalition raids and encouraged further actions against the pro-Syrian government forces and Shi'ite militias who also are trying to gain control of the strategic border point.

"What happened today demonstrates that they cannot reach our territories," Al-Baraa Fares, a spokesman for the rebel group Maghaweer Al Thawra, told VOA. "When they tried, we informed the collation airplanes, which destroyed their convoys."

A U.S. official estimated that "possibly dozens of fighters" convoyed into the restricted area ahead of the airstrike. Another official put the number of pro-government fighters inside the deconfliction zone at a "couple hundred."

"The strike was not a change in policy," but rather an instance of the commander on the ground calling for force protection, according to a third official.

A statement from the coalition Thursday confirmed the deconfliction zone agreement remains in effect.

Jacques also said that Russia had agreed to call the United States to deconflict whenever they planned to operate in the area within 55 kilometers of the base. The Russians had used the hotline less than 24 hours before the Syrians violated the space.

"The line's been up and running," he noted.

The U.S. military says it does not communicate with pro-Syrian government forces and speaks with Russian forces only when needed to prevent miscalculations, since U.S. and Russian aircraft both conduct bombing missions in Syrian skies.

"We will never work with the Assad regime," Brett McGurk, the special presidential envoy for the counter-IS coalition, told Pentagon reporters Friday.

Anti-IS coalition forces have been operating in the al-Tanf area for many months. Their focus has been to train and advise Syrian rebel groups on how best to capture key terrorist-controlled territories on the Syrian southern border with Jordan and Iraq.

The pro-Syrian government forces were 25 kilometers away from al-Tanf base when they were targeted by coalition planes, according to Fares.

Fares said the pro-Syrian government forces tried but failed to receive reinforcement from nearby Shi'ite militias.

Ahed Al Hendi from the VOA Extremism Watch Desk contributed to this report.</s>Earlier in the day, BuzzFeed News reported that a US-led coalition spokesperson has confirmed that coalition strikes in southern Syria struck Syrian government armed forces.

The coalition strikes reportedly occurred near At Tanf town, where US’ and British special operations forces have been training Syrian rebel fighters near the border with Iraq and Jordan.

“The strike did happen. It was against a pro-regime force operating in the vicinity of At Tanf. This regime force was operating within a well-established de-confliction zone,” the defense official told Sputnik.

The US defense official added that the US coalition commander considered the pro-Assad forces as a threat to coalition troops.

“The commander on the ground perceived this force to be a threat to coalition forces,” the defense official said.

It is unclear yet whether the strikes have killed any soldiers or pro-government militia fighters as there has been no official comment from Damascus so far.

The US-led coalition said that the agreement on a de-confliction zone with Russia remains in effect despite the strike on Syrian army.

The United States and Russia signed the bilateral memorandum of understanding in October 2015 to ensure their flight safety during combat missions over Syria.

On Monday, Al-Masdr News reported that Syrian Arab Army soldiers along and militias affiliated with the Iraqi Popular Mobilization Units are preparing to recapture the nearby Tanf Border crossing from Daesh.

Media reports suggested that Syrian rebels have voiced concerns over the Syrian army getting “too close” to the US Special Forces’ base in At Tanf.

In April, Daesh terrorists attempted to take the US base near At Tanf in which three US-backed Syrian rebels were killed.

This was not the first time the US-led coalition intentionally or accidentally struck the Syrian army fighting against Daesh. In the early hours of April 7, the United States launched 59 Tomahawk cruise missiles at the Syrian military airfield in Ash Sha’irat, located about 40 kilometers from the city of Homs. Moreover, on September 17, 2016, US-led coalition aircraft carried out four strikes against the Syrian army near the Deir ez-Zor airport, killing 62 soldiers and wounding some 100.</s>The coalition strikes occurred near At Tanf town, where US' and British special operations forces have been training Syrian rebel fighters near the border with Iraq and Jordan.

"The coalition struck pro-regime forces… after apparent Russian attempts to dissuade Syrian pro-regime movement south towards At Tanf were unsuccessful, a coalition aircraft show of force and the firing of warning shots," the statement said.

The deconfliction memprandum on flights over Syria set up between the United States and Russian military remains in focre despite the US-led coalition's strike on Syrian government troops, the coalition added.

"The agreed upon de-confliction zone agreement remains in effect," the statement said.

The United States and Russia signed the bilateral memorandum of understanding in October 2015 to ensure their flight safety during combat missions over Syria.

On Monday, Al-Masdr News reported that Syrian Arab Army soldiers along and militias affiliated with the Iraqi Popular Mobilization Units are preparing to recapture the nearby Tanf Border crossing from Daesh.</s>U.S.-led coalition jets reportedly struck Syrian and allied forces inside Syria. BuzzFeed News cited a U.S. defense official as confirming the strike was launched by the U.S. That would mark the first time the Syrian regime has been directly targeted by the U.S. since President Trump ordered a missile strike last month in response to the Assad regime’s use of chemical weapons—and they also mark an escalation in the U.S. involvement in the Syrian civil war.

BuzzFeed added the strikes occurred near al-Tanf, near Syria’s border with Jordan and Iraq, where U.S. and U.K. special-operations forces train Syrian rebels.

CBS News reported that the strikes were in response to Syrian regime vehicles violating a deconfliction zone set up around the military base in al-Tanf. It said Assad’s regime had violated the zone twice in recent days. Here’s more:

In one incident, 27 regime vehicles drove within 18 miles of al-Tanf, which breached the 34 mile radius of the army convoy. U.S. aircraft attempted to buzz the regime, but when the convoy didn't turn around, they conducted a strike against some of the vehicles. In the second incident, an unarmed Syrian SU-22 fighter-bomber entered the deconfliction zone and was intercepted by a pair of F-22 fighter aircraft.

Fars, the Iranian news agency that is allied with Iran’s Islamic Revolutionary Guard Corps, reported that 3,000 fighters from Hezbollah, the Iran-backed Lebanese Shia militia, were deployed to Tanf “to prepare the Syrian army and its allies for thwarting the U.S. plots in the region and establish security at the Palmyra-Baghdad road.” It said the Syrian military and others had also been sent to the region.</s>The coalition strikes reportedly occurred near At Tanf town, where US' and British special operations forces have been training Syrian rebel fighters near the border with Iraq and Jordan.

"The strike did happen. It was against a pro-regime force operating in the vicinity of At Tanf. This regime force was operating within a well-established de-confliction zone," the defense official told Sputnik.

The US defense official added that the US coalition commander considered the Syrian army as a threat to coalition troops.

"The commander on the ground perceived this force to be a threat to coalition forces," the defense official said.

On May 4, Russia, Turkey and Iran signed a memorandum on the establishment of safe zones in war-torn Syria as part of the the Astana talks on Syrian settlement. The four zones include the northwestern Idlib province and parts of the neighboring Latakia, Hama and Aleppo provinces, the north of the central Homs province, eastern Ghouta near Damascus and certain parts in the country's southern Deraa and Quneitra provinces. The memorandum on these de-escalation zones took effect on May 6.

On Monday, Al-Masdr News reported that Syrian Arab Army soldiers along and militias affiliated with the Iraqi Popular Mobilization Units are preparing to recapture the nearby Tanf Border crossing from Daesh.

In April, Daesh terrorists attempted to take the US base near At Tanf in which three US-backed Syrian rebels were killed.

This was not the first time the US-led coalition intentionally or accidentally struck the Syrian army fighting against Daesh. In the early hours of April 7, the United States launched 59 Tomahawk cruise missiles at the Syrian military airfield in Ash Sha’irat, located about 40 kilometers from the city of Homs. Moreover, on September 17, 2016, US-led coalition aircraft carried out four strikes against the Syrian army near the Deir ez-Zor airport, killing 62 soldiers and wounding some 100.</s>The U.S. military carried out an air strike Thursday against militia supported by the Syrian government that posed a threat to U.S. and U.S.-backed Syrian fighters in the country's south, U.S. officials told Reuters.

The militia, who numbered in the dozens and drove a tank and a small number of construction vehicles, ignored warning shots from U.S. aircraft and, according to a U.S.-led coalition statement, even "apparent Russian attempts to dissuade" their advance.

One of the U.S. officials, who spoke on condition of anonymity, speculated that the group might have been trying to establish a position near the garrison in Syria used by U.S. and U.S.-backed forces around the town of At Tanf.

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"They were potentially probing to see how close they could get to At Tanf," the official said.

A member of the U.S.-backed Syrian rebel forces told Reuters the convoy comprised Syrian and Iranian-backed militias and was headed toward the Tanf base when they clashed with some rebel forces.

The militia were struck after they had advanced to about 17 miles (27 km) from the base.

"We notified the coalition that we were being attacked by the Syrian army and Iranians in this point, and the coalition came and destroyed the advancing convoy," said Muzahem al Saloum of the Maghawir al Thwra group.

Since they appeared defensive in nature, Thursday's strikes did not suggest a shift in the U.S. military's focus in Syria, which has been on battling Islamic State militants.

U.S. Defense Secretary Jim Mattis said America's role in Syria's conflict was unchanged.

"No. We are not increasing our role in the Syrian civil war. But we will defend our troops," Mattis said, when asked about the strikes.

But the latest move showed that the area around the Tanf garrison in southern Syria could be under pressure.

Tanf is part of a region known as the Badia, which consists of vast, sparsely populated desert territory that stretches all the way to the Jordanian and Iraqi borders and was declared a military priority by Syria's foreign minister earlier in May.

Two months of U.S.-backed rebel advances against Islamic State militants have allowed them to secure swaths of territory in the Badia, alarming the Syrian government and its allies.

But rebel sources had warned last week that the Syrian army and Iranian-backed militia moved hundreds of troops with tanks to the town of Sabaa Biyar, which is in the Badia, and is near the strategic Damascus-Baghdad highway.

That highway was once a major weapons supply route for Iranian weapons into Syria.

A Western intelligence official, speaking on condition of anonymity, said the strike sent a strong message to Iranian-backed militias that have been spearheading the advance that they would not be allowed to reach the Iraq border from Syria.

The U.S.-led coalition did not signal it would cede ground around Tanf.

"Coalition forces have been operating in the At Tanf area for many months training and advising vetted partner forces engaged in the fight against ISIS," according to a statement by the U.S.-led coalition.

U.S. officials said an agreement existed with Russia on a so-called "deconfliction" area around Tanf garrison, meant to avoid an accidental clash of forces.

The statement by the U.S.-led coalition acknowledged a zone but did not offer any details about it, other than to say it was still active.

"The agreed upon deconfliction zone agreement remains in effect," the statement said.

A commander in the alliance fighting in support of Assad called the strike a "warning raid," adding it was not aimed at causing casualties but instead stopping the advance.

Still, the strikes would be the first against fighters aligned with Syria's government since the United States launched cruise missile strikes on a Syrian air base in April.

The April strikes were ordered in retaliation for a chemical weapons attack that Washington blamed on Damascus, and were described as a one-off measure to deter any future chemical weapons use.
United States aircraft bomb a convoy belonging to the Syrian pro-government militia within a so-called "deconfliction zone" around Al-Tanf.