Russia's upper house of parliament has approved President Putin's request for Russian forces to be used in Ukraine.Russia's Black Sea Fleet is based in the Ukrainian region of Crimea, where many ethnic Russians live.

Ukraine has reacted angrily to days of military movements in Crimea, accusing Moscow of trying to provoke the new government into an armed conflict.

Ukrainian officials and some Western diplomats said that a Russian military intervention is already well underway after heavily armed gunmen in unmarked military uniforms seized control of local government buildings, airports and other strategic facilities in Crimea in recent days.