A Hamilton city councillor wants to ban outside groups from doing security duties on city property in an effort to ward off the potential for a deadly incident like the one in Charlottesville.

Matthew Green of Ward 3 says the self-professed "patriot group" Canadian Three Percenters did security detail on July 29, when the Canadian Combat Coalition held a rally at city hall against federal anti-Islamophobia Motion 103.

The rally got heated when anti-fascism demonstrators clashed with coalition members. Now Green wants to ban outside groups from presenting themselves as security to prevent future rallies from getting bloodier.

"We only need to look at Charlottesville to see how these things can escalate," he said.

The move is timely given an Aug. 12 incident in Charlottestown, Va. James Alex Fields Jr. is charged with driving a car into a group of protestors, killing 32-year-old anti-fascism protestor Heather Heyer and wounding at least 19 others. Later that day, two police officers responding to the incidents were killed when their helicopter crashed.

Green says that could happen here, especially if groups like the Three Percenters take root.

The group calls itself non-violent on its Facebook page, although says it trains to "keep our family's and houses safe." The Facebook page shows people in camouflage shooting guns and doing drills, and includes items such as "how to make gunpowder."

On its website, the American version says it "will combat all those who are corrupt."

"We are America's insurance policy," the website says. "We will not see our republic fail. We are everywhere."

CBC News contacted the Canadian Three Percenters on Facebook for comment.

Someone from the site replied, confirming that they did security at the event, adding:

"Are you kidding us CBC? We're a patriot group, not what you people make us out to be," followed by swearing at and then blocking the reporter.

Green said the group "has the right to their freedom of expression. However, they should not be playing any type of security function or any type of paramilitary function within our city."

Rom D'Angelo, the city's director of facilities management, said the Canadian Combat Coalition booked the city hall forecourt to have a rally, and the Canadian Three Percenters showed up too.

Green said he's not about censoring what groups can use the forecourt, but wants to censor who can be there in a security capacity. The rallies are growing, he said, and "I can only see this escalating."

City staff are investigating how to do this.

CBC is seeking comment from the Canadian Combat Coalition.

The Tower is hosting a "solidarity rally with Virginia anti-fascists" at King and James streets from 7 to 10 p.m. Monday night. It also hopes to have a fundraising dinner this week to raise money for medical expenses.

samantha.craggs@cbc.ca | @SamCraggsCBC