Thousands of protesters in Serbia have rallied against President Aleksandar Vucic, demanding early parliamentary elections.

Serbia's president announced Sunday more arrests of anti-government protesters following clashes with police at a massive rally demanding an early parliamentary election. Dozens have already been detained.

Police detained several dozen protesters, while six police officers were reported injured in clashes, Dragan Vasiljevic, the director of police, told a press conference late on Saturday. Vucic said protesters attempted to topple the state. "They (protesters) wanted to topple Serbia, and they have failed," he wrote on his Instagram page.