The Czech prime minister has defended controversial methods used by riot police to break up a techno rave.
Thousands of protesters gathered to denounce the police action
Tear gas and water cannon were used to break up the party of 5,000 ravers at the weekend CzechTek event, leaving 80 injured, including 50 police officers.
Thousands of people have protested outside the interior ministry.
The Czech president criticised the crackdown, but Prime Minister Jiri Paroubek said techno fans were "no dancing children but dangerous people".
Writing in the Lidove noviny newspaper on Tuesday, he said the core of the techno enthusiasts was made up of "obsessed people with anarchist proclivities and international links," who "provoke massive violent demonstrations, fuelled by alcohol and drugs, against the peaceful society".
He expressed regret over the injuries, but said the police only defended themselves against attacks.
Organisers of CzechTek, which has been staged since 1994, say they had permission to hold the event in Mlynec, in the west of the country, close to the German border.
About 1,000 police officers moved in shortly after the event started, saying that the revellers had damaged private property.
They set up blockades and closed off roads around the site to stop more people attending.
President Vaclav Klaus, a former leader of the right-wing opposition Civic Democrats, said in a statement:
"Those who approved the intervention bear full responsibility for damaging trust in the police and creating another split in our country."
Police used tear gas and water cannon to disperse the crowds
Protesters outside the interior ministry on Monday held banners reading: "Down with fascists in the government".
The Czech media has been hotly debating the controversy.
According to a poll by the SC&C polling institute for the Mlada fronta Dnes (Mfd) daily, 70% surveyed said the police action was too tough. Some 44% believed it was necessary, while the same number disagreed.
Mr Paroubek, of the Social Democrats, said comparisons with crackdowns on students by the communist authorities in 1989 were offensive.
"Any analogy drawn with the current savagery of young anarchists is absolutely wrong and expedient," he wrote.