Montenegro's ruling coalition and opposition parties agreed to call an extraordinary session of the parliament's security committee to investigate whether the police used excessive force at an opposition rally on Saturday evening.
The ex-Yugoslav republic's main opposition bloc, the Democratic Front, set up tents in front of the parliament 21 days ago demanding the resignation of Prime Minister Milo Djukanovic and the formation of an interim government pending 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.
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.
The police said 15 demonstrators were detained and four police officers were injured.
The Speaker of the Parliament and leader of the Socialist Democratic Party (SDP), a junior coalition partner in the government, met with some opposition MPs on Sunday morning.
"The security committee will meet this evening," Ranko Krivokapic said. He said the committee will investigate Saturday's protest including "suspicions that there had been a use of excessive force by the police." He said the committee will also investigate whether protestors violated the law and if they had attacked police officers.
"Nobody can be above the law," he said. Djukanovic's Democratic Party of Socialists (DPS) accused the Democratic Front of trying to destroy the country's "constitutional order and stop it in its aim to join Nato", it said in a statement on Sunday. The Democratic Front called for protests on Sunday at 1900 local time (1700 GMT) and invited opposition parties to join them.
"Teargas, batons and shock bombs will not stop us, but motivate us more to persist in our struggle against a totalitarian regime," Andija Mandic, Democratic Front leader told Reuters.