The leader of the opposition Serbian Left party was assaulted at an opposition meeting in the city of Krusevac on Friday.
The Alliance for Serbia said that Borko Stefanovic was knocked down and beaten as he arrived at the meeting.
"A group of thugs armed with metal bars stopped Stefanovic, knocked him down onto the pavement and beat him mercilessly,“ a press release said, adding that two party activists were also beaten when they ran up to help Stefanovic.
Stefanovic was taken to the local emergency centre with serious head injuries while the two activists had teeth knocked out and were hit in the head, it said.
The Alliance for Serbia said the attack on its members is the result of what it called the „dirtiest witchhunt which Aleksandar Vucic‘s regime wages daily against political opponents“.
The Serbian Left released pictures showing the injuries on the back of Stefanovic‘s head.
Senior Democratic Party (DS) Srdjan Milivojevic said the assault was actually directed against all officials from opposition parties present at the meeting which is part of regular activities by the Alliance.
Serbian President Aleksandar Vucic told a news conference on Friday evening that the attackers had been arrested. „The state reacted immediatelly and did its job and showed that Serbia is not a banana republic in which you can hit anyone for any reason,“ he said replying to a reporter‘s question.
The police confirmed later in the evening that two men had been arrested on suspicion of assaulting Borko Stefanovic. A press release said that a third person had been identified as one of the attackers but was still at large.