Many of those at the May 29 night rally in Belgrade were young people, some not even born during Bosnia's 1992-95 war. Dozens of those detained by riot police wearing helmets, protective gear and shields were minors.

The Serbian Radical Party, whose leader is on trial in The Hague, brought in supporters by bus from across Serbia to rally for Mladic. Many came straight from Sunday soccer matches.

During the violence, 32 police and 11 protesters were hurt, and five cars and six shops also suffered damage, police said.

Mladic, indicted for genocide in the 43-month siege of Sarajevo and the massacre of 8,000 Muslims in Srebrenica during the war, was arrested on Thursday in a village 100 km (60 miles) northeast of Belgrade after 16 years on the run.

A Belgrade court ruled on May 27 he was fit enough to face genocide charges at the International Criminal Tribunal in The Hague and has served extradition papers.

His lawyer Milos Saljic has said he would appeal the extradition ruling on Monday.

Mladic's arrest is key to Serbia's bid for European Union candidacy and came just weeks before UN chief war crimes prosecutor Serge Brammertz was due to brief the UN Security Council on Serbia's progress in the hunt for Mladic.