A former senior officer in the Bosnian Serb army has called on other fugitives to surrender, in his first appearance at the war crimes court in The Hague.
Srebrenica was the worst massacre of civilians in Europe since WWII
Ljubisa Beara, who turned himself in in Serbia on Saturday, was indicted more than two years ago in connection with the 1995 Srebrenica massacre.
He did not enter a plea to the genocide charges against him.
More than 7,500 Muslim men and boys from Srebrenica were killed in the most infamous crime of the Balkan wars.
Mr Beara was the head of security for the Bosnian Serb army and responsible for prisoners of war at the time.
In his appearance at the UN tribunal, the former officer appealed to war crimes suspects to "to get rid of the stone that hangs around the neck of our nation".
Correspondents say Serbia and Montenegro has been under mounting pressure to co-operate with the tribunal.
In March 2002 The Hague tribunal indicted Mr Beara on charges of genocide or complicity to commit genocide.
Prosecutors say he was directly responsible for killing Muslim prisoners and forcibly expelling thousands of women and children from Srebrenica.
He is also accused of being part of what the tribunal calls a joint criminal enterprise with, among others, the head of the Bosnian Serb army, General Ratko Mladic - who is still at large.
According to the government of Serbia and Montenegro, Mr Beara said he was giving himself up to protect the interests of the state and those of his family.
In previous extradition cases suspects have been put under intense pressure to surrender rather than be arrested, which is viewed by the authorities as a politically unpopular approach.