Classes in a building at a downtown Montreal university are canceled for the day after more than 250 students occupied it for several hours and ended up clashing with police overnight.

Wednesday marked the first day of a 10-day injunction that L'Université du Québec à Montréal obtained to stop demonstrators from blocking entrances as part of their ongoing protest of provincial budget austerity. The decision to occupy the building came after the university asked police to enforce the injunction.

Clashes broke out Wednesday between those who favor boycotting classes and those who wish to continue attending school. Twenty-two people were arrested earlier.

Some students also attacked police cruisers, tossed garbage cans into the street and ripped up flower beds. Police used tear gas and pepper spray to disperse the students.