Hundreds of people gathered to pray for Radovan Karadzic across the Serb half of Bosnia on Saturday, holding vigils inside churches or marching in protest at his arrest on war crimes charges.

The leader of the Bosnian Serbs in the 1992-95 Bosnia war was indicted for genocide by the United Nations tribunal in The Hague. He was arrested in Serbia last week after 11 years on the run and now awaits extradition, likely in the coming week.

The mostly elderly supporters filed quietly into churches, lit candles and prayed silently for Karadzic to have strength in his trial. Others held his picture and banners reading: "We are with you".

"We are here to support him, and show how much bitterness we feel at this arrest," said Miladin Ilic, 69, an ethnic Serb former resident of Sarajevo who now lives in Pale, one of the main cities in the autonomous Serb Republic.

"We Serbs have suffered for centuries, and this arrest brings a great shock and more sorrow to the Serb people."

Karadzic and his military commander Ratko Mladic are indicted for genocide over the 43-month siege of Sarajevo and the 1995 Srebrenica massacre of 8,000 Bosnian Muslims. Mladic and another war crimes suspect are still at large.

Most Bosnian Serbs see both Karadzic and Mladic as heroic defenders of the Serb nation and say the charges against them are false accusations founded on anti-Serb propaganda.

"More than 200 Bosnian Serb war veterans are ready to testify in The Hague that Karadzic is innocent, and prove that there was also Serb victims in that war," said Slavko Jovicic, member of a veterans' association, who was marching in support of Karadzic. "We are at the court's disposal."

Some in the crowd criticised Bosnian authorities for not allowing Karadzic's family, who live in Pale, to visit him in prison. The travel documents of Karadzic's wife, daughter and son were seized in an effort to choke off his support network.

Bosnia's peace overseer Miroslav Lajcak has said a travel ban on the family will remain in force until it is certain any visit to Karadzic would not influence proceedings against him.

"Lajcak should be expelled, he is showing no support to the Serbian people," said one woman who was holding Karadzic's picture and shouting: "Radovan is our hero". "It is outrageous that they won't let his family go to see him."

The earliest Karadzic can be extradited is Monday, Serbian authorities have said. His lawyer Svetozar Vujacic declined on Saturday to say whether or when he had filed an appeal. "I was instructed by Radovan Karadzic to say nothing," he said.

Serbia's closer ties with the European Union depend on its facing up to its war crimes past and delivering remaining war crime fugitives to the U.N. court.