Montenegrin police have used tear gas to break up a protest by the opposition demanding the government's resignation and an early election in the small Balkan state.

Several hundred opposition leaders and supporters gathered Saturday evening in downtown Podgorica, the capital, and tried to advance through a police cordon. Officers fired tear gas and pushed them away.

Anti-government leaders had staged a days-long protest in a main street in Podgorica, but police removed their tents earlier on Saturday. Opposition parties have vowed to gather again in a bid to force an early election.

The opposition groups earlier this week also staged an anti-NATO protest during a visit by the alliance Secretary-General Jens Stoltenberg to Montenegro.

Opponents have accused Montenegro's government of authoritarian rule and pressure against opponents.