Serbian police Friday launched a second raid in a week in the so far futile search for war crime fugitives, the private Beta news agency said.
Police were checking several locations in Arandjelovac, a town 50 kilometres south of Belgrade, Beta said, quoting the Serbian war crimes prosecutor's office, reported dpa.
A week ago, commandos raided the Belgrade home of the top war crime suspect Ratko Mladic's son, after storming a factory in western Serbia last month.
The arrest of Ratko Mladic, the Bosnian Serb wartime military chief, is a crucial condition for Serbia's closer ties with the European Union.
The International Criminal Tribunal for Former Yugoslavia (ICTY) charged Mladic, allegedly responsible for the massacre of 8,000 Muslims at Srebrenica, with genocide for atrocities committed by his forces during the 1992-95 Bosnian war.
Belgrade officials insisted that they are unaware of Mladic's whereabouts, but eventually admitted that he had military protection even after the strongman president Slobodan Milosevic fell in 2000.
The ICTY chief prosecutor Serge Brammertz is scheduled to report on Belgrade's cooperation with The Hague-based tribunal to the United Nations on Friday.
The EU placed a pre-accession treaty it signed with Serbia last year until Mladic and the other remaining fugitive, the Croatian Serb leader from the 1990s Goran Hadzic, are brought to justice.