Act of war: Russian troops storm base, killing soldier

RUSSIAN forces have reportedly begun storming a Ukrainian military base in the Crimean capital Simferopol, killing one serviceman and wounding an officer.

Ukrainian military spokesperson Vladislav Seleznyov said shots had been fired and one serviceman had died of wounds to his neck and collarbone.

"We have barricaded ourselves on the second floor," a spokesperson told the Interfax news agency.

"The headquarters has been taken and the commander has been taken. They want us to put down our arms but we do not intend to surrender," he said.

"We are being stormed. We have about 20 people here and about 10 to 15 others, including women," an unidentified serviceman told Fifth Channel television.

A second man, a captain, was also injured. Seleznyov said it was unclear who had staged the assault, but described the attackers, as "unknown forces, fully equipped and their faces covered".

Speaking in Kiev today, the interim Ukrainian prime minister Arseniy Yatseniuk declared that the situation had moved from being a political to a military conflict.

"Today, Russian soldiers began shooting at Ukrainian servicemen and this is a war crime without any expiry under a statute of limitations," he said.

The clash came as Russian President Vladimir Putin today signed a treaty to annex Crimea, declaring that the peninsula "has always been an inseparable part of Russia".

Speaking in a televised address to both houses of parliament, Mr Putin told representatives from Crimea's new pro-Russian leadership that their referendum was held "in full accordance with international law".

He said Russia would have been "betraying" the people of Crimea if it had not gone in to help in the wake of the deposition of Ukrainian President Viktor Yanukovych.

But he also denied Russia had ever exceeded the agreed number of troops it was allowed to have in the peninsula under international law.

There was no immediate confirmation that the troops operating in Simferopol today belong to that number.