Hundreds of people had been living in abandoned buildings near city's railway station
Pro-EU candidate Sasa Jankovic, who garnered 16 percent in the April 2 polls compared to 55 percent for Vucic, called for a partial recount of ballots.
"Vucic thief, you stole the elections!" a crowd of several thousand in Belgrade chanted, marching through the centre of the capital.
According to the IPSOS research institute Vucic won about 55 percent of the vote, above the 50 percent threshold required to win in the first round.
Nearly seven million voters will elect new president from among a total of 11 candidates
But Serbia rebuked the move, and its minister in charge of cooperation with the UN tribunal, Rasim Ljajic, said the country would not arrest the three suspects.
Polls suggest current Premier Aleksandar Vucic could win first-round vote, leading to change in post's symbolic nature
6 people were also arrested
We do not need EU', 'Serbia does not trust Brussels', nationalists say
Vucic, who heads the Serbian Progressive Party (SNS) and became premier in 2014, is the frontrunner in opinion polls to succeed fellow SNS member Tomislav Nikolic, who has served as president of the Balkan nation since 2012.
Serbia's national broadcaster RTS reported an injured toll of at least 20.
Former foreign minister Vuk Jeremic and the country's ombudsman, Sasa Jankovic, are also expected to compete.
Rights groups say government is complicit in 'pushbacks' of refugees to Macedonia and Bulgaria, including families dumped in forests with Belgrade, Serbia as well as hundreds of refugees are now living in miserable conditions in makeshift camps
EU foreign policy chief Federica Mogherini says discussions will 'intensify' over coming days
Ties between the two Balkan countries have reached their lowest level since they opened talks to improve relations back in 2011.
In the appeal, Serbian Federation claimed that accepting the Football Federation of Kosovo in UEFA was illegal and violated the rules.
The meeting will be held on January 24th, for normalization of relations between Belgrade and Prishtina.
Intervention comes after diplomatic spat over slogan-covered Serbian train which tried to enter Kosovo
Hundreds of Serbs protested today in Northern Mitrovica for the Belgrade train that was stopped from entering Kosovo.
With temperatures set to fall below freezing and snow on the way, some migrants who have fallen through the safety net are surviving on a single meal a day.
A Belgrade-based human rights group immediately slammed a meeting between the Serbian president and Momcilo Krajisnik, a key ally of Radovan Karadzic