Radovan Karadzic will face charges of genocide at The Hague.
His lawyers said the former Bosnian Serb leader plans to defend himself at the tribunal.
He has been held in a Belgrade prison since his arrest on Monday, awaiting an appeal that is unlikely to prevent his extradition to face genocide charges.
Karadzic's supporters who maintain he is a war hero - clashed with riot police again a day after his arrest.
Al Jazeera's Dan Nolan reports on one of the most wanted men in Europe posing as a Doctor Dragan Dabic.