Clashes broke out between groups of demonstrators and police as a student-led movement returned to Serbia's capital Belgrade on Saturday, demanding an end to President Aleksandar Vucic's 12-year rule.
The populist leader has been accused by critics of consolidating power and undermining democratic checks and balances.
The protest movement erupted some 18 months ago after 16 people were killed when a newly-renovated roof collapsed at a major railway station, blamed on corruption and negligence.
What happened at the latest protest?
According to media reports, tens of thousands of people joined the rally, with many protesters wearing T-shirts with the slogan "Students win" or carrying Serbian flags or banners bearing the names of their town or city.
