Details added (first version posted at 02:56)
Police arrested 70 people Sunday night after a violence erupted at a rally in support of
Ratko Mladic, the arrested Bosnian Serb wartime military chief accused of genocide, dpa reported.
Serbian police director Milorad Veljovic told the national TV RTS that police held the Belgrade streets "fully under control." Several injuries were reported following the clashes.
While a massive police presence remained on central Belgrade streets, the situation appeared to have calmed down by 10:30 pm (2030 GMT), 90 minutes after the rally ended.
Skirmishes broke out when groups of demonstrators began hurling rocks and apparently a few flash grenades at a police cordon securing the rally at a plateau in front of the Serbian Parliament.
Violence started at the end of the 90-minute rally around 9 pm (1900 GMT). Half an hour later, groups of demonstrators were still in a standoff with police in nearby streets.
Police prevented groups of hooligans from reaching the block where many foreign embassies are located. The US, Turkish and German missions had been targeted in the past by Serbian demonstrators.
Several thousand people gathered for the rally in fair weather Sunday evening. The protest was called by the right-wing Serbian Radical Party (SRS), after Mladic's arrest Thursday.
Speakers from the SRS accused President Boris Tadic's governing coalition of treason and called for new elections.
Among those who addressed the crowd was Mladic's son, Darko.
While sizeable, the crowd was far from huge, with Serbian national television estimating the turnout at 10,000. The SRS shrugged off any responsibility for the violence.
Veljovic said earlier that 3,000 uniformed officers and riot police were on duty for the rally.
Accused of genocide by the United Nations war crimes tribunal for atrocities during the 1992-95 Bosnian war, including the massacre of 8,000 Muslims at Srebrenica, Mladic was arrested after nearly 16 years on the run.
Serbian authorities have cleared the path for his extradition to the war crimes tribunal in The Hague. A deadline for an appeal expires Monday.