Ukraine police fire tear gas to disperse protest in Kiev

No casualties were reported in the incident, which occurred when demonstrators began dismantling metal crowd barriers and trying to grab officers' helmets outside the building on Kiev's broad main boulevard.

Thousands of opposition protesters had gathered to rally against what they say is an illegitimate council session.

They say the mandate of the legislature, which is dominated by allies of President Viktor Yanukovich, ended in June and that a new election must be held.

Control of the council in Kiev, a city of 3 million, could give the government or its opponents an advantage in Ukraine's next presidential election in 2015, political analysts say.

The opposition said five protesters were detained in Wednesday's protest. Police did not give a figure but said those who were detained would be charged with hooliganism.