Serbia has increased its reward for the capture of Europe's most wanted war crimes fugitive Ratko Mladic from one million euro (£870,000) to 10 million euro (£8.7 million).
The government also offered one million euro for the arrest of wartime Croatian Serb rebel leader Goran Hadzic.
Wartime Bosnian Serb army commander Mladic is accused by a UN war crimes court of organising the massacre of up to 8,000 Muslim boys and men from Srebrenica in 1995 and besieging the Bosnian capital of Sarajevo for three years.
Hadzic is charged with crimes against humanity during Croatia's war of independence from Yugoslavia from 1991 to 1995.
Both are believed to be hiding in Serbia.