Police fired tear gas and rubber bullets at stone-hurling extremists in downtown Belgrade as ultranationalists protested the government's plans to extradite ex-Bosnian Serb leader Radovan Karadzic to the U.N. war crimes tribunal in The Hague, Netherlands.

In anticipation of clashes July 29, riot police had deployed across the capital and heavily armed antiterrorist troops guarded the U.S. Embassy as busloads of ultranationalists arrived from all over Serbia and Bosnia for the antigovernment rally.

While about 15,000 Serb extremists attended the rally in a main square, several hundred hooligans separated from the group and began hurling stones and burning flares at police.

Later, police fired tear gas and rubber bullets at groups of demonstrators, trying to push them away from the square as the rally ended.

Belgrade's emergency clinic reported that 46 people were injured, including 25 policemen and 21 civilians. Most were lightly injured, doctors said.

Karadzic faces 11 charges at the U.N. tribunal, including genocide and conspiracy to commit genocide.

Waving posters of their "Serb Hero," protesters had flooded into the city. Many had carried banners and wore badges with Karadzic's name and picture. Some chanted slogans against President Boris Tadic's pro-Western government and called for his death.

Police estimated the turnout at only 15,000 people — far fewer than expected. The last major nationalist rally, in February after Kosovo's declaration of independence, drew 150,000 people and led to an attack on the U.S. Embassy.