Police and student protesters clashed in the center of the Greek capital on Thursday after a demonstration against government plans to allow private universities.

Demonstrators in Athens attacked police cordons, set fire to trash dumpsters and threw stones at riot police near parliament and later during clashes along the capital’s narrow streets. Police responded with tear gas and made several arrests.

The center-right government wants to legalize privately run universities in a bill that is due to go before parliament this month, arguing that the reform would prevent skilled people from leaving the country and make higher education more relevant to the labor market.

But the plan has sparked several protests, including an ongoing campaign to occupy university buildings in protest, which has disrupted classes and forced some academic authorities to reschedule upcoming exams.

The protesters left the building peacefully, but scuffles broke out between police and a crowd gathered outside.

Conservative Prime Minister Kyriakos Mitsotakis has urged university administrators to seek police assistance to counter what he described as “illegal actions” by student protesters.

“It is as if 10 people got together and took a vote to rob the grocery store next door,” he said in a radio interview earlier this week.

Opponents of the reforms argue that the changes would undermine state universities and ultimately limit access to higher education for people from low-income families.

The left-wing main opposition party, Syriza, said that the university bill would be a “tombstone” for public education, noting that Greece doesn’t have any fee-paying public universities unlike many other European countries.