(dpa) - Thousands of supporters of war crimes suspect Radovan Karadzic rallied Tuesday amid a strong police presence, challenging Serbia's government not to hand him over to the UN tribunal in The Hague.
Some estimates put the crowd in Belgrade's downtown pedestrian mall at 10,000. The US embassy earlier said up to 100,000 people might attend.
Serbia's ultranationalist opposition Radical Party organized the rally, hoping for the biggest show of defiance yet to pro-Western President Boris Tadic since Serbian authorities arrested Karadzic last week, ending 12 years on the run.
A large "Freedom for Serbia" hung on a stage set up on a central square. Protesters waves Serbian flags, sang nationalist songs and hoisted banners with pictures of Karadzic, the former Bosnian Serb leader, and war crimes fugitive Ratko Mladic.
After the one-hour rally, the demonstrators planned to march through central Belgrade.
Strong police forces were in place at major embassies, government buildings, and on the march route's streets.
When the ultranationalist party organized a major protest against Kosovo's independence from Serbia in February, mobs torched the US and other embassies and looted stores in the Serb capital.
The US embassy in Serbia closed early Tuesday because of the rally and warned citizens to avoid downtown Belgrade.
City police chief Slobodan Vukolic said his officers would prevent a repeat of violent protests. "Members of the Belgrade police will especially pay attention to the safety of all the citizens, media representatives, diplomatic buildings and other important city landmarks," he told reporters.
A top Radical leader, Aleksandar Vucic, pledged to keep the rally peaceful.
Karadzic's extradition to face genocide charges bogged down Tuesday in a tug-of-war between his lawyers and a Serbian court that has to approve his handover to The Hague.
The tribunal has indicted Karadzic on charges including genocide and crimes against humanity for his role in the 1992-95 Bosnian war, which left an estimated 100,000 dead. The genocide charges relate to the 1995 Srebrenica massacre of Bosnian Muslim men and boys
A lawyer for the former Bosnian Serb leader has said he would file the appeal by last Friday, but the special war crimes court in Belgrade has yet to receive such a motion, court spokeswoman Ivana Ramic told reporters.
The court has no legal deadline to wait for the appeal and will wait "a reasonable amount of time" before extraditing Karadzic, Ramic said Tuesday. She didn't specify when that might happen.
Dusan Ignjatovic, top Serbian official for cooperation with The Hague said Karadzic will be extradited to The Hague by the end of the week.
Ignjatovic told Tanjug state agency that said Karadzic's lawyer apparently failed to appeal against extradition.
"I don't think the appeal exists. If it did, it would have arrived in the court by now," Ignjatovic, who heads the Serbian government's office of cooperation with The Hague, told Tanjug
Since Karadzic's July 21 arrest, hundreds of protesters have gathered daily in Belgrade to denounce pro-European President Boris Tadic and the arrest of a "Serbian hero." Some of the protests turned violent.
Karadzic's status as one of the top war crimes suspects in the Balkans, and the uncertainty surrounding his appeal, raised speculation by media and local analysts that he will be spirited to The Hague in the early morning, likely from an army airport in Belgrade.
Serbia's reward for full cooperation with the tribunal is the hope of eventual European Union membership. That would likely also require handing over Mladic, a former general who served as Karadzic's military chief.