Media playback is unsupported on your device Media caption Ukrainian soldiers are trapped on their own base as Daniel Sandford reports 
 
 Ukraine has ordered a full military mobilisation in response to Russia's build-up of its forces in Crimea. 
 
 Prime Minister Arseniy Yatsenyuk said Ukraine was "on the brink of disaster". 
 
 In Crimea, Ukrainian soldiers faced off with Russian soldiers surrounding their bases while the Russian army is said to be digging trenches on the border with mainland Ukraine. 
 
 Media playback is unsupported on your device Media caption US Secretary of State John Kerry said Russian troops moving into the Ukraine region of Crimea was a "brazen act of aggression" 
 
 US Secretary of State John Kerry has warned Russia could be ejected from the Group of Eight developed nations. 
 
 Russian President Vladimir Putin, he said, was "not going to have a Sochi G8, he may not even remain in the G8 if this continues," referring to a planned summit in Russia in June. 
 
 "He may find himself with asset freezes, on Russian business. American business may pull back, there may be a further tumble of the rouble. 
 
 "You just don't in the 21st Century behave in 19th Century fashion by invading another country on completely trumped-up pretext," Mr Kerry told the CBS program Face the Nation. 
 
 The facts on the ground are such that Russia, to a large extent, is already in control there Moscow's Ukraine gamble 
 
 The UK has joined the US, France and Canada in suspending preparations for the Sochi summit. 
 
 Nato is conducting emergency talks, saying Russia's actions threaten "peace and security in Europe". 
 
 US President Barack Obama called Russian troop deployments a "violation of Ukrainian sovereignty". 
 
 Russian soldiers continue to occupy key sites on the Crimean peninsula, including airports and communications hubs, although there has been no actual violence and they have been openly welcomed by some sections of the population. 
 
 In the east Ukrainian city of Donetsk, apparent members of the disbanded elite police riot unit Berkut appeared in full uniform at a pro-Russian rally. 
 
 At the scene Crowds of excited pro-Russian Crimeans have gathered near the gates of the marines' base in Feodosia. A deadline demanding the marines pledge loyalty to the new government in Crimea has passed. Despite threats to attack the base, local Cossacks, who act as law and order here, continue to stand in a chain near the gates. Behind the gates I could see freshly-made dugouts, but no-one is inside them at the moment. A couple of marines in sand-coloured flak jackets are manning the gates from the inside. The street leading to the base is blocked by two armoured personnel carriers, with another closer to the gates. When asked whose APCs and soldiers they were, a Cossack said "Russians", but he didn't know whether they came from Black Sea Fleet base in Sevastopol or Russia. From time to time the loudspeaker on a van near to the entrance of the base calls on the marines to recognise the new pro-Russian government in Crimea, and not to act upon "criminal orders from Kiev". Any filming activity in the crowds is risky - we saw cameramen and photographers being harassed. One cameraman had to leave the approach to the base and another was led away by a policeman. Text of Putin's request to use troops What is so dangerous about Crimea? Crimea profile 
 
 In Moscow, police detained dozens of people at anti-war rallies outside the Russian defence ministry and other places in the city centre, while elsewhere in the city a pro-Putin march was held. 
 
 Military build-up 
 
 Ukrainian national security officials announced several other measures on Sunday 
 
 The armed forces would to be put on "full combat readiness" 
 
 Reserves to be mobilised and trained 
 
 Foreign minister to seek help from US and UK leaders in guaranteeing its security 
 
 Emergency headquarters to be set up 
 
 Security to be boosted at key sites, including nuclear plants 
 
 Airspace to be closed to all non-civilian aircraft 
 
 Meanwhile, Ukraine withdrew coast guard vessels from two ports in Crimea and moved them to other bases in the Black Sea and Sea of Azov. 
 
 A Ukrainian army base was surrounded by Russian troops at Perevalnoye, south of the Crimean regional capital Simferopol. An Orthodox priest has arrived in an attempt to mediate. 
 
 In Sevastopol, Ukrainian naval officers found their headquarters occupied by Russian troops and were unable to go to work. 
 
 Admiral Yuriy Ilyn, who was until recently commander of the Ukrainian navy and served briefly as head of Ukraine's armed forces under ousted President Viktor Yanukovych, told the BBC's Christian Fraser at the scene that the armed forces were "hostages of the situation". 
 
 Media playback is unsupported on your device Media caption Admiral Yuri Ilyn: "I'm very sorry that Ukrainian soldiers and sailors are hostages of this situation" 
 
 In the eastern port city of Feodosia, a group of about 100 Ukrainian marines were also blockaded into their base by armed men demanding they pledge loyalty to the region's new pro-Russian authorities. 
 
 In the north of Crimea, at Armyansk on the Isthmus of Perekop, the BBC saw what appeared to be Russian soldiers digging trenches. The isthmus is strategically vital as it joins Crimea to the rest of Ukraine. 
 
 Russian ground troops have been active in Crimea - home to Russia's Black Sea Fleet - for the past few days. 
 
 On Saturday the newly elected pro-Moscow leader of Crimea, Sergiy Aksyonov, appealed to Mr Putin for help to ensure peace on the peninsula. 
 
 The interim government in Kiev does not recognise Mr Aksyonov and his government. 
 
 Image copyright AP Image caption Ukrainian soldiers were surrounded by Russian troops at Perevalnoye, one of several stand-offs on the peninsula 
 
 Image copyright Getty Images Image caption Russian soldiers surrounded a Ukrainian base at Perevalnoye in Crimea 
 
 Image copyright Getty Images Image caption One pro-Russian family posed for photos with the soldiers 
 
 Image caption Russian soldiers were apparently digging trenches on the strip of land joining Crimea to mainland Ukraine 
 
 Image copyright AFP Image caption Apparent members of Ukraine's disbanded riot unit, Berkut, turned out at a pro-Russian rally in the eastern city of Donetsk 
 
 Image copyright Reuters Image caption A march was held in Moscow in support of President Putin's policy on Crimea and Ukraine 
 
 Image copyright AP Image caption But there were small anti-war protests too. "Ukrainians - I am ashamed to be a Russian!" - placard of one protester arrested in Moscow 
 
 Image copyright AP Image caption Meanwhile pro-EU protesters rallied once again in the capital Kiev 
 
 Image copyright AFP Image caption Anti-Putin protesters in Kiev mocked the Russian leader with a placard showing him as Adolf Hitler 
 
 Russian 'violation' 
 
 Media playback is unsupported on your device Media caption Ukraine's interim Prime Minister Arseniy Yatsenyuk says his country is "on the brink of disaster" 
 
 Late on Saturday, Mr Obama held a 90-minute telephone conversation with Mr Putin and urged him to pull forces back to bases in Crimea. 
 
 Mr Putin said Moscow reserved the right to protect its interests and those of Russian speakers in Ukraine. 
 
 President Putin submitted his request for troops to the Russian parliament on Saturday "in connection with the extraordinary situation in Ukraine and the threat to the lives of Russian citizens", the Kremlin said. 
 
 Mr Obama, the White House said, told Mr Putin that the appropriate way to address any concerns was "peacefully through direct engagement" with the Ukrainian government and international mediating bodies. ||||| Unidentified gunmen wearing camouflage uniforms block the entrance of the Crimean Parliament building in Simferopol, Ukraine, Saturday, March 1, 2014. The discord between Russia and Ukraine sharpened... (Associated Press) 
 
 KIEV, Ukraine (AP) — Russian President Vladimir Putin has asked parliament for permission to use the country's military in Ukraine, the Kremlin said Saturday. 
 
 Putin said the move is needed to protect ethnic Russians and the personnel of a Russian military base in Ukraine's strategic region of Crimea. 
 
 "I'm submitting a request for using the armed forces of the Russian Federation on the territory of Ukraine pending the normalization of the socio-political situation in that country," Putin said in a statement released by the Kremlin. 
 
 He sent the request to the Russian legislature's upper house, which has to approve the motion, according to the constitution. 
 
 In Crimea, the pro-Russian regional prime minister had earlier claimed control of the military and police there and asked Putin for help in keeping peace, sharpening the discord between the two Slavic neighbor countries. 
 
 It was the latest escalation following the ouster of Ukraine's pro-Russian president last week by a protest movement aimed at turning Ukraine toward the European Union and away from Russia. 
 
 Armed men described as Russian troops took control of key airports and a communications center in Crimea on Friday. Ukraine has accused Russia of a "military invasion and occupation" — a claim that brought an alarming new dimension to the crisis, and raised fears that Moscow is moving to intervene on the strategic peninsula where Russia's Black Sea fleet is based. 
 
 Ukraine's population is divided in loyalties between Russia and Europe, with much of western Ukraine advocating closer ties with the European Union while eastern and southern regions look to Russia for support. Crimea is mainly Russian-speaking. 
 
 Crimean's prime minister, Sergei Aksyonov, declared that the armed forces, the police, the national security service and border guards in the region will answer only to his orders. 
 
 Ukrainian Prime Minister Arseny Yatsenyuk opened a Cabinet meeting in the capital, Kiev, by calling on Russia not to provoke discord in Crimea, a peninsula on the Black Sea. 
 
 "We call on the government and authorities of Russia to recall their forces, and to return them to their stations," Yatsenyuk was quoted as saying by the Interfax news agency. "Russian partners, stop provoking civil and military resistance in Ukraine." 
 
 ___ 
 
 Vladimir Isachenkov reported from Moscow. ||||| SIMFEROPOL, Ukraine — Russia’s move to seize control of Ukraine’s Crimean Peninsula on Saturday led Ukraine to call up its military reserves on Sunday and warn Moscow against further incursions as Western powers scrambled to find a response to the crisis. 
 
 
 
 
 
 
 
 
 
 A day after the Russian Parliament granted President Vladimir V. Putin broad authority to use military force in response to the political upheaval in Ukraine that dislodged a Kremlin ally and installed a new, staunchly pro-Western government, the Ukrainian government in Kiev threatened war if Russia sent troops further into Ukraine. 
 
 Russian troops stripped of identifying insignia but using military vehicles bearing the license plates of Russia’s Black Sea force swarmed the major thoroughfares of Crimea on Saturday, encircled government buildings, closed the main airport and seized communication hubs, solidifying what began on Friday as a covert effort to control the largely pro-Russian region. 
 
 The announcement of the reserve mobilization was an attempt by the rattled new government in Kiev to draw a line against Mr. Putin, an effort expected to continue later on Sunday when NATO holds an emergency meeting on Ukraine and the British foreign secretary, William Hague, visits Kiev in a sign of Western support. 
 
 What began three months ago as a protest against the Ukrainian government has now turned into a big-power confrontation reminiscent of the Cold War and a significant challenge to international agreements on the sanctity of the borders of the post-Soviet nations. 
 
 Mr. Putin convened the upper house of Parliament in Moscow on Saturday to grant him authority to use force to protect Russian citizens and soldiers not only in Crimea but throughout Ukraine. Both actions — military and parliamentary — were a direct rebuff to President Obama, who on Friday pointedly warned Russia to respect Ukraine’s territorial integrity. 
 
 Mr. Obama accused Russia on Saturday of a “breach of international law” and condemned the country’s military intervention, calling it a “clear violation” of Ukrainian sovereignty. 
 
 In Crimea, the situation was calm but hardly placid on Sunday morning, with fewer soldiers visible on the streets. Some heavily armed soldiers without insignia had taken up positions around small Ukrainian military bases, but without trying to enter them. 
 
 At Perevalnoye, a small Ukrainian base some 15 miles south of Simferopol on the road to Yalta, scores of soldiers with masks, helmets and goggles, in unmarked uniforms, ranged along one wall of the base. Inside there were about two dozen Ukrainian soldiers, equipped with an armored personnel carrier. 
 
 Col. Sergei Starozhenko, 38, the Ukrainian commander, told reporters the unmarked troops had arrived about 5 A.M. and “they want to block the base.” 
 
 He said he expected them to bring reinforcements and call for talks. Asked how many men he has at his command, he said simply: “Enough.” 
 
 In Sevastopol, pro-Russian “self-defense” forces were blocking the entrances of the main Ukrainian naval headquarters. There was no sign of Russian troops, Ukrainian officers were at work inside and armed Ukrainians guards were on patrol behind the closed gates. 
 
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 Pro-Russia demonstrators put up a banner reading: “Sevastopol without Fascism,” and urged Ukrainian officers to come over to their side rather than serve the “illegal fascist regime” in Kiev. The demonstrators shoved packs of cigarettes, candy and bottles of water through gate for the Ukrainian guards. 
 
 “They have to make a choice -- they either obey the fascists in Kiev or the people,” said Sergei Seryogin, a pro-Russia activist outside. Kiev, he said, “is illegal power” and should be ignored by all military and civil officials. 
 
 Photo 
 
 Russia kept up its propaganda campaign on Sunday in defense of the takeover, citing undefined threats to Russian citizens and proclaiming “massive defections” of Ukrainian forces in Crimea, which appeared to Western reporters to be unfounded. The state-owned Itar-Tass news agency cited the Russian border guard agency claiming that 675,000 Ukrainians had fled to Russia in January and February and that there were signs of a “humanitarian catastrophe.” 
 
 Russia insists that its intervention is only to protect its citizens and interests from chaos and disorder following the still unexplained departure from Kiev of former president Viktor F. Yanukovych. 
 
 “If ‘revolutionary chaos’ in Ukraine continues, hundreds of thousands of refugees will flow into bordering Russian regions,” the border service said, according to Tass, providing one more unsubstantiated justification for Russian military intervention. 
 
 Late Saturday, Ukraine’s acting president, Oleksandr Turchynov, said he had ordered Ukraine’s armed forces to full readiness because of the threat of “potential aggression.” He also said he had ordered stepped-up security at nuclear power plants, airports and other strategic infrastructure. 
 
 Prime Minister Arseniy P. Yatsenyuk, said he was “convinced” Russia would not intervene militarily in eastern Ukraine, “since this would be the beginning of war and the end of all relations” with Russia. 
 
 While Ukrainian forces in Crimea offered no resistance, there is concern that Russia might use the same pretext of citizens in peril to move forces into eastern Ukraine, which has many Russian speakers and heavy industry with close ties to Russia. 
 
 Large pro-Russia crowds rallied on Saturday in the eastern Ukrainian cities of Donetsk and Kharkiv, where there were reports of violence. In Kiev, the Ukrainian capital, fears grew within the new provisional government that separatist upheaval would fracture the country just days after a winter of civil unrest had ended with the ouster of Mr. Yanukovych, the Kremlin ally who fled to Russia. 
 
 In addition to the risk of open war, it was a day of frayed nerves and set-piece political appeals that recalled ethnic conflicts of past decades in the former Soviet bloc, from the Balkans to the Caucasus. 
 
 Mr. Obama, who had warned Russia on Friday that “there will be costs” if it violated Ukraine’s sovereignty, spoke with Mr. Putin for 90 minutes on Saturday, according to the White House, and urged him to withdraw his forces back to their bases in Crimea and to stop “any interference” in other parts of Ukraine. 
 
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 In a statement afterward, the White House said the United States would suspend participation in preparatory meetings for the G-8 economic conference to be held in Sochi, Russia, in June, and warned of “greater political and economic isolation” for Russia. 
 
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 Continue reading the main story Rostov-on-Don 50 Miles Don River UKRAINE Sea of Azov RUSSIA CRIMEA Simferopol Airport Simferopol Belbek Airport Sevastopol Black Sea 
 
 The Kremlin offered its own description of the call, in which it said Mr. Putin spoke of “a real threat to the lives and health of Russian citizens” in Ukraine, and warned that “in case of any further spread of violence to Eastern Ukraine and Crimea, Russia retains the right to protect its interests and the Russian-speaking population of those areas.” 
 
 In Britain, Prime Minister David Cameron said that “there can be no excuse for outside military intervention” in Ukraine. 
 
 Canada said it was recalling its ambassador from Moscow and, like the United States, suspending preparations for the G-8 meeting. 
 
 At the United Nations, the Security Council held an emergency meeting on Ukraine for the second time in two days. The American ambassador, Samantha Power, called for an international observer mission, urged Russia to “stand down” and took a dig at the Russian ambassador, Vitaly I. Churkin, on the issue of state sovereignty, which the Kremlin frequently invokes in criticizing the West over its handling of Syria and other disputes. 
 
 “Russian actions in Ukraine are violating the sovereignty of Ukraine and pose a threat to peace and security,” she said. 
 
 The secretary general, Ban Ki-moon, also spoke with Mr. Putin on Saturday and described himself as “gravely concerned” and urged Mr. Putin to negotiate with officials in Kiev. 
 
 Mr. Yanukovych’s refusal, under Russian pressure, to sign new political and free trade agreements with the European Union last fall set off the civil unrest that last month led to the deaths of more than 80 people, and ultimately unraveled his presidency. The country’s new interim government has said it will revive those accords. 
 
 Ukraine’s acting president, Oleksandr V. Turchynov, said at a briefing in Kiev on Saturday evening that he had ordered Ukraine’s armed forces “to full combat readiness.” A Ukrainian military official in Crimea said Ukrainian soldiers had been told to “open fire” if they came under attack by Russian troops or others though it was unlikely they could pose a serious challenge to Russian forces. 
 
 Officials in Kiev demanded that Russia pull back its forces, and confine them to the military installations in Crimea that Russia has long leased from Ukraine. 
 
 “The presence of Russian troops in Crimea now is unacceptable,” said acting Prime Minister Arseniy P. Yatsenyuk. Decrying the Russian deployment as a “provocation,” he added, “We call on the government of the Russian Federation to immediately withdraw its troops, return to the place of deployment and stop provoking civil and military confrontation in Ukraine.” 
 
 Photo 
 
 Sergey Tigipko, a former deputy prime minister of Ukraine and one-time ally of Mr. Yanukovych, said he flew to Moscow in hopes of brokering a truce. 
 
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 The fast-moving events began in the morning, when the pro-Russia prime minister of Crimea, Sergei Aksyonov, declared that he had sole control over the military and the police, and appealed to Mr. Putin for Russian help in safeguarding the region. He also said a public referendum on independence would be held on March 30. 
 
 The Kremlin quickly issued a statement saying that Mr. Aksyonov’s plea “would not be ignored,” and within hours the upper chamber of Russia’s Parliament had authorized military action. 
 
 The authorization cited Crimea, where Russia maintains important military installations, but covered the use of force in the entire “territory of Ukraine.” Parliament also asked Mr. Putin to withdraw Russia’s ambassador to the United States. 
 
 By nightfall, the scores of armed men in uniform who first appeared on Crimea’s streets on Friday had melted away from the darkened center of Simferopol, vanishing as mysteriously as they arrived. 
 
 For the new government in Kiev, the tensions in Crimea created an even more dire and immediate emergency than the looming financial disaster that they had intended to focus on in their first days in office. 
 
 A $15 billion bailout that Mr. Yanukovych secured from Russia has been suspended because of the political upheaval, and Ukraine is in desperate need of financial assistance. Mr. Yatsenyuk, the acting prime minister, had said that the government’s first responsibility was to begin negotiations with the International Monetary Fund and start to put in place the economic reforms and painful austerity measures that the fund requested in exchange for help. 
 
 In Crimea, however, officials said they did not recognize the new government, and declared that they had taken control. 
 
 Mr. Aksyonov, the regional prime minister, said he was ordering the regional armed forces, the Interior Ministry troops, the Security Service, border guards and other ministries under his direct control. “I ask anyone who disagrees to leave the service,” he said. 
 
 As soldiers mobilized across the peninsula, the region’s two main airports were closed, with civilian flights canceled, and they were guarded by heavily armed men in military uniforms. 
 
 Photo 
 
 Similar forces surrounded the regional Parliament building and the rest of the government complex in downtown Simferopol, as well as numerous other strategic locations, including communication hubs and a main bus station. 
 
 Near the entrance to Balaklava, the site of a Ukrainian customs and border post near Sevastopol, the column of military vehicles with Russian plates included 10 troop trucks, with 30 soldiers in each, two military ambulances and five armored vehicles. 
 
 Soldiers, wearing masks and carrying automatic rifles, stood on the road keeping people away from the convoy, while some local residents gathered in a nearby square waving Russian flags and shouting, “Russia! Russia!” 
 
 As with the troops in downtown Simferopol, the soldiers did not have markings on their uniforms. 
 
 There were also other unconfirmed reports of additional Russian military forces arriving in Crimea, including Russian ships landing in Feodosiya, in eastern Crimea. 
 
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 Crimea, while part of Ukraine, has enjoyed a large degree of autonomy under an agreement with the federal government in Kiev since shortly after Ukrainian independence from the Soviet Union. 
 
 The strategically important peninsula, which has been the subject of military disputes for centuries, has strong historic, linguistic and cultural ties to Russia. The population of roughly two million is predominantly Russian, followed by a large number of Ukrainians and Crimean Tatars, people of Turkic-Muslim origin. 
 
 In eastern Ukraine, which is also heavily pro-Russian, demonstrators in Kharkiv rallied and then seized control of a government building, pulling down the blue-and-yellow Ukrainian flag and raising the blue, white and red Russian one. Scores of people were injured as protesters scuffled with supporters of the new government in Kiev. 
 
 In Donetsk, also in the east, several thousand people held a rally in the city center, local news agencies reported, with many chanting pro-Russian slogans and demanding a public referendum on secession from Ukraine. 
 
 In Moscow, the parliamentary debate on authorizing military action was perfunctory, but laced with remarks that echoed the worst days of the Cold War. Underscoring the extent to which the crisis has become part of Russia’s broader grievances against the West, lawmakers focused on Mr. Obama and the United States as much as on the fate of Russians in Ukraine. 
 
 “All this is being done under the guise of democracy, as the West says,” Nikolai I. Ryzhkov, one member of Parliament, said during the debate. “They tore apart Yugoslavia, routed Egypt, Libya, Iraq and so on, and all this under the false guise of peaceful demonstrations.” He added, “So we must be ready in case they will unleash the dogs on us.” 
 
 Yuri L. Vorobyov, the body’s deputy chairman, said Mr. Obama’s warning on Friday was a cause for Russia to act. “I believe that these words of the U.S. president are a direct threat,” he said. “He has crossed the red line and insulted the Russian people.”
– Tensions in the Ukraine just keep escalating. Although President Obama warned Russia not to send troops, Vladimir Putin today got official permission to do just that. The Russian president asked parliament to let him send forces to the "territory of Ukraine" to protect ethnic Russians in the region of Crimea and possibly elsewhere, reports AP. And in a not-so-surprising development, lawmakers agreed unanimously, reports CNN. Earlier, the pro-Russian prime minister of Crimea had made a formal request of his own for Putin's help. The Ukraine government in Kiev, meanwhile, says Russia already has sent 6,000 troops to Crimea, even if it hasn't acknowledged as much, reports the BBC. The upshot is that "the Black Sea peninsula appeared to slip beyond Kiev's control," says Reuters. And it quotes one political analyst who says "the scenario of Crimea's withdrawal (from Ukraine) has been accelerated." Soldiers presumed to be either part of the Russian military or at least backed by the military control the airports, government buildings, and the main communications center in Crimea. Airspace around the main airport in Simferopol has been shut down.