The United Nations in Kosovo accused Serbian officials on Tuesday of orchestrating violent clashes in the north in which a Ukrainian policeman was killed and dozens of other officers were wounded. A NATO official said additional U.S.

By RADUL RADOVANOVIC By Radul Radovanovic The Associated Press KOSOVSKA MITROVICA, Kosovo Serb demonstrators attacked international peacekeepers with rocks, grenades and Molotov cocktails Monday, setting off the worst violence in Kosovo since it declared independence from Serbia last month.

An explosion Monday injured five international peacekeepers in Kosovo as they stormed a courthouse occupied by Serb protesters, officials said. Three U.N. police officers and two NATO soldiers were injured by an apparent hand grenade blast.

NATO peacekeepers were deployed after Kosovar Serbs protested Kosovo's independence by torching two border crossings staffed by Kosovar and U.N. forces.

By Anne Penketh Diplomatic Editor Several thousand Serbs in the Kosovan town of Mitrovica have demonstrated against the likelihood that the province will declare independence from Serbia.