Confrontations between police and protesters continued in Montreal Saturday as dozens of demonstrators were arrested outside a convention centre.

Police said 89 people were arrested Saturday after trying to disrupt the second day of a conference on the development of northern Quebec. Police had arrested a 24-year-old man earlier in the day for obstruction of justice.

In the wake of the protest, which was declared illegal at about noon, conference attendees were searched to ensure demonstrators didn't enter the event.

Saturday's demonstration went ahead despite the cold and rainy weather.

"I think people are starting to get frustrated," Myriam Moore, a 21-year-old student at Universite de Quebec a Montreal, told The Canadian Press.

"The police are abusing their power."

Protesters were issued a warning before police moved in to start making arrests. Those arrested were put on city buses, and will likely be fined and charged for breaking municipal bylaws, CTV Montreal's Aphrodite Salas reported.

However, some protesters could still face criminal charges, including mischief.

The heavy rain and heavy police presence sent the protesters home by later afternoon Saturday. There were no reports of vandalism.

Protests against a planned tuition hike, Plan Nord and police reaction to previous demonstrations have raged across Quebec in the past few weeks. A raucous protest on Friday appeared to indicate that demonstrators were growing more aggressive.

Seventeen people were arrested outside Palais des congres de Montreal on Friday as protesters hurled rocks at police officers and smashed store windows.

Inside the centre, Quebec Premier Jean Charest condemned the violence.

"We're not going to accept that," Charest told reporters on Friday. "We're certainly not going to be governed in Quebec because some people think violence and intimidation is the way to get things done."

On Saturday, student Fabrice Marcoux said protests are getting more violent because "the government has pushed us to our limits.

"When you're pushed back and you feel there is no issue, there is no exit possible, you have to act in an irrational manner to make the movement possible," he told CTV Montreal.

For about 10 weeks now, thousands of college and university students across Quebec have been rallying against Charest's plan to increase tuition fees by $325 annually over the next five years.

Demonstrations, however, have grown more and more nuanced.

Students and environmentalists banded together Friday to protest the Plan Nord, Charest's political project to develop the province's north.

"It's not just the tuition increase," said Alexis Remartini, 18, who took the bus from St-Hyacinthe for the protest. "The movement has grown to include other things we don't agree with."

A small group of representatives from the Mohawk and Innu communities held up signs protesting Charest's northern development plan. They walked for three weeks, covering 900 kilometres, to attend Saturday's demonstration.

They expressed concern about the violence.

"We're feeling kind of uneasy about being here," Stuart Myiow, of the Kahnawake Mohawk Council, told reporters. "We brought our children. We didn't bring them out here because we didn't feel good about their safety."

Charest has a 25-year plan to develop a 1.2-million-square kilometre stretch of the region. The premier says it will create some 500,000 jobs, but his claims have been met with skepticism as opponents see it as nothing more than a marketing gimmick and a sellout of Quebec's resources.

On Friday, Charest began his speech about 45 minutes behind schedule, a talk that for months some had expected might serve as a launching pad into an election campaign.

At one point, Charest snuck in a dig at the protesters outside.

"For the students knocking on our doors, we could offer them work up north," he told the audience in French.

The comment riled Francois Legault, leader of the Coalition Avenir Quebec, who has called on Charest to apologize to demonstrators.

"You don't make jokes at a conflict that is there for 10 weeks now," Legault said at the start of the CAQ's first convention in Victoriaville.

The CAQ had intended to use Friday to unveil seven new candidates, but the protests back in Montreal appeared to overshadow other topics at the gathering.

"We cannot afford to continue like that in Quebec," said Legault. "It's our young people, it's our children that are in the streets."

Another protest is planned for Sunday, which is also Earth Day.

With a report from CTV Montreal's Aphrodite Salas, Laura Casella and Maya Johnson and files from The Canadian Press