Kiev is moving to withdraw its military from Crimea and to distance itself dramatically from Russia, as Moscow's troops and local allies seize Ukrainian bases on the Black Sea peninsula.
One Ukrainian soldier and one pro-Russian militiaman were killed when one facility was stormed, and Ukraine's acting president Oleksandr Turchinov said "technical and technological measures" would be taken unless Crimean authorities freed Kiev's servicemen.
It is not clear how many Ukrainians were taken captive yesterday, but Mr Turchynov said the commander of the country’s navy, Admiral Serhiy Haiduk, was among them.
Mr Turchynov did not specify how he would retaliate if the men were not freed, but Crimea gets the vast majority of its water, energy and other supplies from elsewhere in Ukraine.
Crimea has no land link with Russia, which has moved to annexe the region of two million people, and Kremlin leader Vladimir Putin yesterday ordered the urgent construction of a bridge across the straits that divide them.
'Dangerous situation'
"The continuing efforts by Russian forces to seize Ukrainian military installations are creating a dangerous situation," White House spokesman Jay Carney said last night.
“We condemn these actions. Russia should immediately begin discussions with the Ukrainian government to ensure the safety of Ukrainian forces in the Crimean region of Ukraine.”
The head of Ukraine's national security council announced that Kiev planned to pull its military out of Crimea and to urge the United Nations to make Russia do the same.
Andriy Parubiy said the government would appeal to the UN to “recognise Crimea as a demilitarised zone and take measures necessary for Russian forces to leave Crimea” and it would also prepare for “the re-deployment . . . of Ukrainian forces from the occupied territories to mainland Ukraine”.
The country's leaders may present their request to UN secretary general Ban Ki-moon if he visits Kiev as planned tomorrow. He is due to meet Mr Putin in Moscow today.
Territorial integrity
Mr Parubiy also said Kiev was requesting military exercises with the US and Britain, which under the 1994 Budapest Memorandum that guaranteed Ukraine's sovereignty and territorial integrity in exchange for Kiev's relinquishment of its nuclear arsenal. Russia was the third guarantor.
Having earlier threatened to seize Russian assets in response to the annexation of Crimea, Kiev yesterday revealed plans to give up its associate membership of the Commonwealth of Independent States, a Moscow-led ex-Soviet bloc, and to introduce visas for Russian visitors.
Moscow immediately threatened to impose the same travel restrictions on Ukrainians, in a move that could cause major difficulties for the huge numbers of people from both countries who cross their shared border to work, trade and visit family and friends.
Moscow tightened its grip on Crimea, meanwhile, raising Russia’s flag over more Ukrainian military bases, giving Russian passports to people in the region, and unveiling urgent plans to raise pensions to the standard Russian level.
The West continued to condemn Russia’s annexation of Crimea, rejecting Mr Putin’s assertion that he was righting a historical mistake by restoring Kremlin control over the region, and his claim to be protecting Russian-speakers from “fascists” linked to Ukraine’s new pro-western government.
Baltic states
"As long as Russia continues on this dark path, they will face increasing political and economic isolation," US vice president Joe Biden said in Lithuania, where he reassured the former Soviet Baltic states – now EU and Nato members – that "we're in this with you together".
Nato's secretary-general, Anders Fogh Rasmussen, called the Ukraine crisis a "wake-up call" and "the gravest threat to European security and stability since the end of the cold war".
