Pro-Russian protesters storm building

More than 3000 pro-Russian protesters have stormed the regional administration building in the eastern Ukraine city of Lugansk, journalists at the scene report.

A vanguard of around 20 youths armed with metal bars broke a window to get inside the building on Tuesday, which was not protected by police.

They pulled down the building's Ukrainian flag, replacing it with a Russian one, and opened the building's doors to the waiting crowd.

Inside the building's courtyard, around 100 riot police massed together in a defensive position behind their shields in a stand-off with the protesters, who demanded they disarm.

"The police must be with the people and must swear allegiance to us," declared the leader of the pro-Russian "Lugansk self-defence group".

Later, around 700 protesters overran the building housing the public prosecutor's offices and headed to the police station, the Interfax news agency reported.

Pro-Moscow militants in Lugansk, a city of 465,000 inhabitants near the Russian border, seized the local SBU security services building three weeks ago.