Following two shootings in which 18 people were killed, tens of thousands of people protested against the government in Belgrade on Friday. They blamed the killings on a culture of violence that, according to its opponents, officials have allowed to flourish unchecked.

In Serbia’s first mass shooting at a school, a teenage teenager killed nine students and a security officer on May 3. A day later, a 21-year-old man killed eight people outside of Belgrade.

Opposition parties, which organised the demonstration, say the government led by President Aleksandar Vucic’s Serbian Progressive Party (SNS) has failed to rein in media that have promoted violence and to act against criminal elements in society.

Recent Serbian reality TV shows have featured convicted criminals including murderers and shown men beating up women.

Protesters called on Vucic, Interior Minister Bratislav Gasic and the head of Serbia’s security agency to resign.

“I came here to protest against living in this country the way it is now, against violence which is visible everywhere in public speech, in media, against this evil we are living in and against the way this country is being led,” said a university professor who gave her name as Vera.

“This number of people makes me optimistic.”

Reuters estimated the protest, the third of its kind this month, drew a crowd in the tens of thousands.

The government denies the opposition parties’ allegations and accuses them of organising the protests for political gain.

Gasic on Friday admitted in parliament that several criminal complaints had been filed against the 21-year-old shooter but were never processed.

In a counter-rally in Pancevo, a town outside Belgrade, Vucic accused the opposition of trying to use the mass shootings for self promotion. “Serbia is fed up with your revolutions,” he said .