PRISTINA (Reuters) - An explosive device was thrown at Kosovo’s parliament building on Thursday evening, a policeman on the scene said, adding that there were no casualties.

Kosovo media reported that two motorcyclists fired a rocket propelled grenade as they drove near the parliament building. The police did not confirm media reports.

The parliament is next to the government’s building on a busy street in the center of Pristina. After the explosion, a special police unit sealed off the area around the parliament, a Reuters witness reported.

In the past 10 months the landlocked state of 1.8 million has seen tensions rise among political parties. Opposition MPs released tear gas inside the parliament several times in a protest over an EU-brokered accord with Serbia giving more autonomy to Serb dominated municipalities. Opposition supporters clashed with the police several times during the same period.

On Thursday morning the Kosovo government asked the parliament to ratify a border agreement with Montenegro, disputed by opposition parties that have said it gives away some 8,000 hectares of Kosovo land.

A major opposition party called its supporters to protest against the border deal in front of the parliament earlier on Thursday, but the crowd quickly dispersed because the issue was not put on the agenda.

Adopting a border deal with Montenegro is a precondition for Kosovo to get a visa-free travel regime to the Schengen zone as other countries in the region including Serbia, Albania, Montenegro, Macedonia and Bosnia were given in 2010.

Kosovo declared independence from Serbia in 2008 and is still not recognized by Belgrade. It has signed a trade and political pact with the EU but it is still not recognized by five member states: Spain, Cyprus, Romania, Greece and Slovakia.