Ukraine crisis: Russian flags at Donetsk government building

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.