Anti-corruption protesters in Serbia set fire to the Valjevo offices of the country's ruling political party, city leaders said, amid clashes sparked by the deadly collapse of a rail station in November.

The offices of the the ruling Serbian Progressive Party (SNS) have been set on fire during a fifth night of unrest in a row that saw fresh clashes between anti-government protesters and riot police.

Violence escalated across Serbia as anti-government protests entered their fifth consecutive night. In Valjevo, masked protesters set fire to the ruling Serbian Progressive Party (SNS) offices before clashing with riot police.