A spokesman for Kosovo's police said the Kosovo Serbs broke through two entrance gates and then replaced the U.N. flag with a Serbian one.
"The regional U.N. representative is negotiating with Serb leaders to overcome the situation," said Besim Hoti, spokesman for Kosovo's police in the Serb- dominated city of Kosovska Mitrovica, where the court is located.
The Serbs have held daily protests in front of the court since Kosovo declared independence from Serbia last month. Dozens of U.N. riot police didn't intervene when the protesters forced their way in Friday.
The protesters have been seeking to take control of local institutions that have been run by the U.N. since the end of the war in Kosovo in 1999. The crowds have prevented international and ethnic Albanian judges from returning to work at the court.
During earlier protests outside the court, U.N. and local staff were forced to evacuate after Serbs rioters targeted the building with several small hand grenade explosions.
The storming of the U.N. courthouse appeared to have been coordinated with Belgrade, which has defied Kosovo's declared statehood by saying it will assume authority in northern Kosovo.
The Kosovo Serbs have already tried to take control of a stretch of rail line in northern Kosovo in defiance of Kosovo's government. Hundreds of Serb policemen have handed over their badges and weapons rather than submit to Kosovo authorities.
Predominantly ethnic Albanian Kosovo has been under U.N. control since 1999, when NATO launched an air war to stop Solobodan Milosevic's crackdown on ethnic Albanians.
Güncelleme Tarihi: 14 Mart 2008, 13:44