Thousands of people had gathered in a march towards the city's campus to demand new elections after alleged corruption. According to the news agency Beta, some had thrown bottles and flares at the police.
Eleven police officers were injured in the clashes. How many demonstrators were injured is unclear.
The protests against the regime and corruption in the country have been ongoing since November last year when 16 people died in a ceiling collapse at a train station in Novi Sad.
President Alexandar Vucic accuses the demonstrators of threatening stability and security in the country. According to Vucic, several demonstrators have been arrested and even more taken into custody by the police.
The people of Serbia should know that the state is stronger than anyone else. It will always be that way, says Vucic.