Protesters in Novi Sad threw flares and red paint on the City Hall after a concrete canopy collapse at the railway station killed 14 people.
Police used tear gas as some protesters threw stones and broke windows.
Serbian President Aleksandar Vucic condemned the violence, warning of consequences.
Protesters demanded justice for the victims, with opposition activists blaming corruption and poor oversight.
The incident has sparked calls for top officials to resign, the Associated Press has reported.
As officials promise accountability, critics doubt a thorough investigation, noting government control over the judiciary.
Written by B.C. Begley
