Thousands of Serbs took to the streets of central Belgrade on Saturday to protest what they say were rigged in the Dec. 17 parliamentary election, which the right won, AFP reported.

It was the 13th consecutive demonstration since the results of parliamentary and local elections were announced, according to which Serbian President Aleksandar Vučić’s SNS party, in power since 2012, won 46% of the vote compared to 23.5% for the opposition coalition.

The opposition contested the results, citing numerous irregularities, including that Bosnian Serbs were illegally allowed to vote in the capital. International observers also reported numerous violations.

Saturday’s demonstration was organized by a group of intellectuals, artists and celebrities known as ProGlass (a pun on both “proclaim” and “vote”). Pro-Glass began as a campaign to get people to vote, and its proclamation later turned into a protest against fraud.

But the protesters who gathered Saturday came from all sides, from the main opposition coalition Serbia Against Violence to student and youth groups that have been demonstrating for nearly two weeks.

“Students aged 18-20 were accused of attempting to overthrow the constitutional order and were put under house arrest. Is this a sign of fair elections?”, one of the leaders of the student movement Emilia Milenkovic said on Saturday. “We just ask that our voice be heard, at least during the voting.”

University professor Philip Eidus welcomed the fact that “students these days are giving us lessons in civic responsibility and courage.” “We reject these stolen elections, student arrests and police torture,” he added.

On Friday, students called by the group “Borba” (“struggle”) managed to block a street in the center of Belgrade.

Symbolic place / Marinika Tepic and hunger strike / The opposition demands to cancel the elections

Protesters have consistently called for the election to be annulled and for rigging to be seriously investigated so that new elections can be held in six months.

On Saturday, the crowd especially cheered opposition leader Marinika Tepic, who had been on hunger strike since December 18 and had to be helped to the podium.

“The only thing I can tell you is that everything has already been said. These elections must be canceled,” she said before going to the hospital and announcing the end of her hunger strike.

The meeting place around the Terazije fountain is symbolic, in people’s memory it is associated with four days of demonstrations in March 1991, the first major protests against the then leader Slobodan Milosevic.

Demonstrators denouncing the disputed results of Serbian parliamentary elections attacked Belgrade’s city hall last Sunday, smashing windows before being pushed back by police. About thirty people were arrested.