Police fired tear gas and rubber bullets at stone-hurling extremists in downtown Belgrade tonight as ultranationalists protested the government's plans to extradite ex-Bosnian Serb leader Radovan Karadzic to the UN war crimes tribunal.
In anticipation of clashes, riot police had deployed across the capital and heavily armed anti-terrorist troops guarded the US embassy as busloads of ultranationalists had arrived from all over Serbia and Bosnia for the anti-government rally dubbed "Freedom for Serbia."
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 riot police.
Later, police fired tear gas and rubber bullets at large groups of demonstrators, trying to push them away from the square as the rally ended. Police blocked off streets in several areas of Belgrade, stopping traffic and not allowing demonstrators to pass.
A Belgrade emergency clinic reported that more than two dozen people were injured in the clashes, including a Spanish TV journalist, and said more injured were expected. Doctors said no one was in a life-threatening condition.
The downtown area was strewn with debris after the clashes, littered with glass from smashed-up shop windows and garbage from overturned cans. Ambulance sirens blared as paramedics raced to help the injured.
Karadzic faces 11 charges at the UN tribunal, including genocide and conspiracy to commit genocide.
He is accused of masterminding the 1995 slaughter of 8,000 Muslim men and boys in Srebrenica and the more than three-year siege of Sarajevo that left 10,000 people dead.
Singing nationalist songs and waving posters of their "Serb Hero," protesters had flooded into the city earlier in the day. 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.
Still, 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 US Embassy amid a violent looting spree.
At the rally, Aleksandar Vucic, leader of the Serbian Radical Party, called for Tadic's government to be overthrown.
"Thank you for showing that Serbia is not dead, although it is being killed by Boris Tadic," Vucic told the crowd. "Thieves and bandits are ruling Serbia."
"We will fight for Serbia and Serbia will be free," he added, setting off thunderous applause and chants of "Uprising! Uprising!"
Karadzic spent nearly 13 years on the run before being arrested last week in Belgrade, only a few weeks after Tadic's government came to power. He is still revered by many as a wartime hero for helping to create the Bosnian Serb mini-state.
Luka Karadzic told the crowd that his brother should be tried in Serbia and not at the UN war crimes tribunal in The Hague, Netherlands.
"It is still not too late to prevent Karadzic's extradition to The Hague," he said.
Ttoday's protest was seen a test for Tadic's government, which is much more pro-Western than its predecessor, and the president had warned extremists to remain peaceful.
"Everyone has the right to demonstrate, but they should know that law and order will be respected," Tadic said.
US Embassy officials had advised Americans to avoid downtown Belgrade and the building was heavily guarded during the rally by special troops armed with machine guns wearing masks. After February's mass rally, the US Embassy was partly burned and protesters went on a looting spree, smashing shops and McDonald's restaurants.
Those protesters were angry that the United States had recognised Kosovo, a former province of Serbia, as an independent country.
It remained unclear today whether Karadzic's lawyer had actually filed an appeal against his extradition to the UN tribunal.
Karadzic's lawyer claimed he sent the appeal by registered mail before a midnight Friday deadline. But the postal service said it did not have the letter and Serbian court spokeswoman Ivana Ramic said the court didn't either.
If an appeal does not arrive, the court's investigative judge could rule to extradite Karadzic to UN tribunal without considering Karadzic's objection.
Karadzic's nephew Dragan Karadzic was seen today delivering two large suitcases to the Belgrade prison for his uncle.
Tadic's government hopes Karadzic's arrest will strengthen the country's bid for membership in the European Union. Serbia had been accused previously of not searching for war crimes fugitives sought by the UN tribunal.