A day of rolling student protests in downtown Montreal started off with police declaring a blockade at the Banque Nationale illegal.

The demonstrations Wednesday took place over 12 hours in what organizers are calling a "marathon of intensive vindication."

A new group of protesters set off every hour from Victoria Square, following different routes through the city’s core.

Protesters started the morning at the square and moved to the Banque Nationale tower, where other demonstrators were already gathering and blocking entrances.

Hundreds of workers were stuck outside as police assessed the situation.  

They declared the demonstration illegal just before 8:30 a.m. ET and moved workers away from the protesters. Police told those blocking the entrances to leave or they could face arrest.

Fifteen minutes later, tactical officers moved in and dispersed the group with an irritant spray.

In Quebec City, a group of about 60 protesters occupied a CIBC bank branch near the national assembly.  Police moved in to escort them out of the building about 20 minutes later, only to see the group cross the street and do the same thing at a Banque Nationale branch.

Student groups have organized near-daily demonstrations since they declared a unlimited boycott on classes nearly two months ago.

At issue is an increase that will see fees rise by $1,625 over the next five years.

The government has refused to back down on the increases despite the student unrest.

The province's universities and CÉGEPs are now warning students they’ve reached the tipping point and risk losing their school year if they continue to boycott classes. 

Education Minister Line Beauchamp has said colleges and universities should continue to offer courses, regardless of whether students attend or not.

University of Montreal student Alex Callisto said he joined the protest Wednesday to show his solidarity with students across the province.

He said at this point, he's still optimistic students won't be forced to re-take a semester's worth of courses, even if they continue their boycott.

"The semester was never cancelled and we feel the repercussion would be too great for that to happen," he said. "We're willing to sacrifice and see what will happen with the government."

Classes resumed Tuesday at the Cégep de Matane and Alma College, where students voted last week to end their boycott.

Thousands of third and fourth yearstudents at Laval University in Quebec did the same and returned to class Tuesday morning. 

In all, 4,800 students are still on strike at Laval University. 

With files from the Canadian Press