BELGRADE, Serbia — Serbian police removed street blockades in the capital Belgrade early Monday that were set up as part of a protest over a spate of arrests of anti-government protesters after a massive rally demanding an early parliamentary election.

Thousands of demonstrators placed metal fences and garbage containers at various locations in Belgrade and elsewhere throughout the country Sunday evening, including a key bridge over the Sava River in the capital. Protesters say they plan to return Monday.

Police said in a statement that a number of people have been detained without specifying how many. Video posted on social media showed police vehicles driving at high speed through a blockade in one Belgrade street and people fleeing in panic.

The blockades are part of persistent dissent against the government of populist President Aleksandar Vucic that started after a train station canopy crashed in the country’s north, killing 16 people.

Protesters have demanded justice for the victims of the canopy collapse in Novi Sad on Nov. 1, which many in Serbia blame on corruption-fueled negligence in state infrastructure projects.

Tens of thousands of people gathered Saturday at a student-led protest in Belgrade to call for the snap vote they hope will oust Vucic’s right-wing government. Groups of protesters clashed with police after the official part of the rally ended. Dozens were later detained.

Vucic has refused to call the election, which is scheduled to be held in 2027. University students and professors are a key force behind nearly eight months of almost daily protests and Vucic has accused them of “terror” and attempts to destroy the country.

Nearly 50 officers and 22 protesters were injured in clashes late Saturday. Riot police used batons, pepper spray and shields to charge at demonstrators who threw rocks and other objects at police cordons. Nearly 40 people face criminal charges over the clashes, police said.

Authorities also have detained at least eight university students for alleged acts against constitutional order and security, accusing them of planning attacks on state institutions. Protesters have demanded their immediate release.

Critics say Vucic has become increasingly authoritarian since coming to power over a decade ago, stifling democratic freedoms while allowing corruption and organized crime to flourish, which he has denied.

Serbia is formally seeking entry to the European Union, but Vucic’s government has nourished relations with Russia and China.