Confrontations between students and police have erupted for a second consecutive day following the reopening of Quebec's universities.
Striking students at the Université de Montréal have been attempting to force the cancellation of certain classes to protest back-to-school legislation passed this spring.
As they did on Monday, students clashed with the university's security guards and Montreal police as they reportedly sought to disrupt a film class.
Montreal police said they had charged 10 people so far, though the operation was still ongoing Tuesday afternoon.
The student protesters ended up disrupting a psychology class, having mistaken it for the film class they were looking for.
Protesters said they were only disrupting classes in departments where student associations had voted to continue striking over the Liberal government's tuition hike.
About five per cent of the university's students – less than 3,000 of its more than 60,000 students – are still on strike.
University officials sought police assistance on Monday, the first day of class following a winter session that was interrupted by the strike.
Police issued notices to 19 students, advising them they were under investigation for violating the back-to-school legislation, better known in the province as Bill 78.
The bill sets out stiff penalties, ranging from $1,000 to $35,000, for anyone who blocks access to class.
Police have said they would only intervene if requested by the university. They said it was students, not the university, who called for their presence Tuesday.
"They were students who told us there was a quarrel on the second floor," said Ian Lafreniere, the chief spokesperson for the Montreal police.
"There were security guards who were being pushed, bullied by the suspects."
Students countered that police acted to catch them off-guard as they sought classes to disrupt, cornering them in a hallway.
"Even the people who had to attend to their needs were being blocked," said Charles Philippe Casgrain. "These are sordid methods, given that they dropped the charges (against many of the detained) and let us go."
Meanwhile at Montreal's other major French-language university – the Université du Québéc a Montréal – students also continued to seek the cancellation of certain classes, but police were not called to intervene there.
In most instances, the student activists found classes already empty.
Students have been given the option of being able to withdraw without penalty from classes they were enrolled in when the strikes began last winter.