Gathering in front of the Serbian presidency in central Belgrade, several hundred staunch supporters of the Serbian Radical Party (SRS) demanded the authorities give up the country's bid to become a European Union member in protest at the acquittal.

The ICTY ruled Thursday to clear Haradinaj, former Kosovo prime minister and a wartime rebel chief of the Kosovo Liberation Army (KLA), and two of his comrades on charges of committing war crimes against Serb civilians during the 1998-1999 conflict in Kosovo.

"We do not blame those (judges) in the Hague, but those who give them orders and these are the US, EU and NATO," Natasa Jovanovic, a top SRS official, told the rally.

Surrounded by anti-riot police, the protesters waved the Serbian flag and that of Russia, the Balkan country's traditional ally.

"We do not want into EU," read one placard in the crowd, while other protesters had posters of SRS leader Vojislav Seselj, who has also been on trial before the Hague-based International Criminal Tribunal for the former Yugoslavia (ICTY) for his role in the Balkans wars in the 1990s.

Protesters also chanted the name of Bosnian Serb wartime military chief Ratko Mladic, currently on trial before the ICTY for genocide committed during the 1992-1995 war in Bosnia.

Haradinaj's acquittal came less than two weeks after that of two Croatian generals charged with war crimes against Serbs during the 1991-1995 war there.

It was met with indignation in Serbia, whose leaders accused the ICTY of bias, saying no high-ranking official in the former Yugoslavia had yet been convicted of crimes against Serbs.

Serbia is an EU member candidate but a date to start accession talks has not yet been set.