Clashes took place between Greek riot police and protesters in Athens late Tuesday night, during which authorities say two policemen were injured and nine people were arrested.

The clashes took place after a demonstration involving around 400 calling for the closure of a maximum-security prison, as promised by the Syriza-led government prior to its election in January, and the release of members of the Conspiracy of Fire Nuclei, an anarchist terrorist group.

A further 21 people were temporarily detained. Charges brought included attempted grievous bodily harm, arson and vandalism.

Following a march from the University of Athens to the Greek parliament, around 70, mainly youth, gathered outside the old building of the National Technical University of Athens, attacking shops and burning at least two cars. Police arrived and the protesters threw petrol bombs and rocks. Police responded with tear gas.

Fighting later erupted at Exarchia square and surrounding streets that lasted until the early hours of Wednesday morning.

The clashes follow days of protests and occupations against the maximum security prison and in support of the imprisoned members of the Conspiracy of Fire Nuclei, a nihilist group responsible for firebombing of banks, luxury car dealerships and the attempted parcel bombing of embassies.

Attacks on Syriza by opposition parties for its supposed leniency last Friday prompted the alternate minister for public order, Yiannis Panousis, to call for the suppression of the protests. He was supported by high level government officials, including a pledge from Prime Minister Alexis Tsipras’ office that the government “remained steadily committed to defending the nation of laws, rights and law and order.”

Renewed clashes on Sunday between environmental protesters and miners over the controversial Hellas Gold mining operation in northern Greece led to complaints by local residents that they were assaulted by riot police and miners.

Panousis again led calls for the police to act. “People may get killed in Skouries [the location of the mine] if we don’t deal properly with the issue,” he said.

That same day, Syriza deputy Katerina Iglezi, who took part in the protest, accused the riot police of colluding with miners and attacking local residents with tear gas leaving four injured. The Greek Reporter noted that “Iglezi told Greek radio that it is inconceivable that three hundred miners broke the police block, including seven police buses, and attacked protesters with sticks and stones without any reaction from the police.”