FEARS of a military conflict over Crimea intensified last night when President Vladimir Putin won the backing of parliament for his decision to send in troops and Ukraine responded by putting its own forces on combat alert.

The escalation in the crisis came amid signs that violent unrest against the new pro-western government in Kiev was spreading from the Crimean peninsula to eastern Ukraine. Both areas are dominated by ethnic Russians.

During a tense 90-minute telephone call last night, President Barack Obama urged Putin to withdraw his forces to bases in Crimea and to “refrain from any interference elsewhere in Ukraine”.

Obama said Russia’s “continued violation of international law” would lead to its political and economic isolation but he did not threaten concrete retaliation beyond