The protests first began in response to the beating-up of an opposition politician in a southern city.

Thousands of people took to the streets of the Serbian capital Belgrade for the third consecutive week to protest against the government of President Aleksandar Vucic.

More than 5,000 people marched towards the Serbian state broadcaster RTS on Saturday – widely seen as supportive of Vucic – before moving to the government headquarters.

The protests, which first began in response to the beating-up of opposition politician Borko Stefanovic during a rally in a southern city, have escalated and now include calls for greater accountability and more freedom of speech.

Stefanovic was approached by a group of young men in hoodies who smashed his head and briefly knocked him unconscious.

Al Jazeera’s Marko Subotic, reporting from Belgrade, said the number of protesters on Saturday exceeded those seen in previous weeks.

“This was the largest protest of citizens because they are not organised by any political party but was actually organised by some public figures and student organisations, albeit backed by opposition parties in Serbia,” Subotic said.

“They will return next Saturday to tell President Vucic, who has been in power for six years, they don’t agree with the current situation in Serbia, especially that there is no freedom of speech and opposition leaders can’t be heard on national television, including Serbia’s public service.”

Vucic mocked the first rally in Belgrade, saying it was small and that “even if there were five million” he would not cede to their demands.

The second protest was held under #1od5miliona (one of five million).

Although Serbia is nominally a democratic society with political opposition and free elections, Vucic’s firm grip on power has made it difficult for opponents to make their voices heard or answer verbal outbursts against them.

Vucic has publicly condemned the attack on Stefanovic and the police swiftly arrested the assailants, but opponents like Dragan Djilas say he has fostered an “atmosphere of violence” that made such an attack possible.

His Progressive Party has dominated in the three parliamentary elections since 2012. Vucic started a five-year term as president last year.

The Serbian opposition, weakened by internal strife, corruption scandals and low exposure on state and pro-government media since Vucic took over, has been fully marginalised.