Some groups are struggling with whether to participate in this Sunday’s St. Patrick’s Day parade in Montreal, after the Collective Opposed to Police Brutality announced it would hold a demonstration coinciding with the parade.

The collective has a history of violent clashes with police, and its planned demonstration has already prompted Scouts Canada to drop out of this year’s parade.

Kevin Murphy, spokesperson for the United Irish Societies of Montreal, which runs the parade, told CBC's Daybreak that Scouts Canada did not consult with organizers before pulling out.

“It’s disappointing if any group decides to pull out, especially since the police and Mayor Denis Coderre have assured us that the situation is under control, and the organizers of the demonstration indicated the target of the demonstration is not the parade, not the participants, not the spectators," said Murphy.

"We are totally confident the parade will go off without a hitch.”

Group already clashed with police Sunday

Another demonstration organized by the Collective Opposed to Police Brutality Sunday in downtown Montreal was declared illegal as soon as it got underway and ended with one arrest and nearly 100 tickets being given out to demonstrators.

Scouts Canada issued a statement Friday saying its troops would not be participating in Montreal’s parade because of the potential for violence. The group has refused to comment further.

Scouts Canada is encouraging its members to participate in St. Patrick's Day parades in other communities, including Hudson on Saturday, March 21 and Châteauguay on March 29.

The Girl Guides organization says it won't comment for the time being.

Marching band says it's not worried

Miranda Clayton, president of the McMaster University marching band from Hamilton, Ont. says her group will stay in the parade.

“We always brief our members on safety anyway. I figure it would be a little bit silly for us to drop out at this point when we’ve already done so much fundraising.”

Clayton says most of her band’s members are over 18.

She says the marching band has an emergency plan in place.

“If there’s trouble, the drum major who is the person who leads the parade will just instruct us to march faster or instruct us to turn a different corner," she said.

"If things went completely nuts and everybody got separated, everybody has my number, everybody can text me and a mass text can be sent for a common meeting point.”

The St. Patrick’s Day parade starts at 12 p.m. ET at Fort Street and Ste-Catherine Street and is to move east along Ste-Catherine to Phillips Square.

The protest is set for 1:30 p.m. Norman Bethune Square, at the corner of de Maisonneuve Boulevard West and Guy Street.