MONTREAL - The aborted spring semester at Montreal's two main French universities resumed Monday, as did student protests that saw blockades and arrests.

Demonstrators at the University of Montreal were taken into custody after they occupied classrooms and heckled students and professors.

There were similar scenes Monday at the University of Quebec at Montreal (UQAM). One professor at the downtown school said he had no choice but to stop teaching when protesters arrived and began screaming and banging on desks.

"I had to leave the room because I was ordered to by security guards, otherwise I would have stayed," he said.

Premier Jean Charest had postponed the spring semester at 25 community colleges and university faculties in the Montreal area that had been hit by sometimes-violent blockades during a student strike over tuition hikes.

Community-college students voted this month to end their six-month boycott. Students at the three main French universities were divided, with some deciding to go back to class and other voting to continue their strike.

Some at UQAM who had waited all summer to resume their spring semester were livid as roaming groups of protesters blocked some classes and disrupted others.

"This is a waste of time," one woman told QMI Agency after being forced out of class. "They need to let us study."

On Mount Royal, at the University of Montreal, a police presence didn't stop protesters from occupying at least three classrooms shortly before 11 a.m.

Police intervened when people blocked access to an emergency exit.

About 30% of all post-secondary students boycotted classes from February to May, and blockades and window-smashing protests led to thousands of arrests and made international headlines.

The crisis led the education minister to resign and Premier Jean Charest called an election for Sept. 4.

He said the vote will allow Quebecers to choose between his law-and-order stance and the pro-blockade position held by the separatist Parti Quebecois.