The office of Yugoslav President Vojislav Kostunica denied tonight he had told a Kosovo news agency that US forces had arrested wartime Bosnian Serb leaders Radovan Karadzic and Ratko Mladic.
"The president did not say anything like that," said Neda Stanisavljevic, who heads the president's information office.
"I can assure you that the president did not give any such statements to any Kosovo agency," she told Reuters.
Other Yugoslav and Serbian officials said they had no knowledge of any arrests of Mladic and Karadzic, two of the world's most wanted men accused of genocide during the 1992-95 Bosnian war.
Yugoslav Interior Minister Zoran Zivkovic told Reuters: "No, we don't have such information. If that had happened on our territory we would have been informed."
Both men were indicted for the 1992-1995 siege of Sarajevo and for the 1995 massacre of up to 8,000 Muslim men and boys in the eastern town of Srebrenica, seen as Europe's worst atrocity since World War Two.
Russia's Itar-Tass news agency, monitored by the BBC in London, earlier said Mr Kostunica had told a Kosovo news agency that US special forces had just arrested the two men, each indicted twice by the UN war crimes tribunal in The Hague.
In a report datelined Rome, Itar-Tass said Mr Kostunica had given an interview to the UPIKosovo news agency and that he had said Belgrade authorities had begun the procedure of their extradition to The Hague tribunal.