Ukraine crisis: Russian flags at Donetsk government building
7 April 2014 Last updated at 21:44 BST
Security officials in Ukraine are being sent to the eastern cities of Donetsk, Luhansk and Kharkiv following the occupation of several government buildings by pro-Russian groups.
In Donetsk, the people who seized the regional administration building have announced the creation of a sovereign "people's republic".
They have also called for a referendum and asked Moscow to send in a peacekeeping force.
The BBC's Steve Rosenberg reports from outside the government buildings in Donetsk.