Montenegro's police used teargas on Saturday to disperse hundreds of anti-government protesters outside the parliament building in the capital Podgorica and local media said several people had suffered light injuries.
The ex-Yugoslav republic's main opposition bloc, the Democratic Front, set up tents in front of the parliament 20 days ago demanding the resignation of veteran Prime Minister Milo Djukanovic and the formation of an interim government pending fresh elections.
Early on Saturday morning the police removed the tents to unblock the city's main street, prompting the Democratic Front to call for the evening protests.
The demonstrators hurled bottles at the police who responded by firing teargas and beating some people at the front of the crowd, including prominent opposition leader Nebojsa Medojevic, a Reuters witness said.
Police declined to comment on the incident.
Critics say the tiny Adriatic country of 680,000 is run as a fief by a political elite largely unchanged over the past 20 years, a description the government rejects.
Montenegro is a candidate for European Union membership and is also expecting an invitation to join NATO later this year.
But Western govenrments and rights groups remain concerned over the level of organised crime and graft, which especially flourished during the breakup of Yugoslavia in the 1990s. Montenegro will hold a parliamentary election next year.