Canadian Prime Minister Justin Trudeau gestures during his election campaign tour stop in Brantford, Ontario, Canada on Sept. 6. (Carlos Osorio/Reuters)

TORONTO — Hours after Prime Minister Justin Trudeau vowed that he wouldn’t back down in the face of the “anti-vaxxer mobs,” protesters — many of them opposed to coronavirus vaccinations and public health measures — threw gravel at him at a campaign stop on Monday evening.

The incident occurred while Trudeau was boarding his campaign bus after an event at a brewery in London, Ontario, a city some 120 miles southwest of Toronto. Videos posted to social media of the episode show protesters throwing gravel in the direction of the prime minister and some of the reporters traveling with him. Trudeau turned toward the direction the gravel was coming from and boarded the bus.

Speaking to reporters on a Liberal campaign plane, Trudeau said that some of the projectiles “might have” hit his shoulder, comparing it to when a woman threw pumpkin seeds at him in 2016.

“There was little bits of gravel,” he told reporters, seeking to dismiss the incident. “It’s no big deal.”

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It was the latest ugly scene in a 36-day federal election campaign that has not been short of them. Vandals have defaced candidate lawn signs with antisemitic graffiti. Candidates of all political stripes have reported being targeted with sexist and racist slurs.

Trudeau last month called a snap federal election for Sept. 20, betting that his handling of the public health and economic crises wrought by the pandemic would help him to regain a majority in the House of Commons. With under two weeks before the vote, his Liberals are running neck-and-neck with the Conservatives.

From the early days of the campaign, Trudeau has sought to position vaccine mandates as a wedge issue. Polls show that Canadians overwhelmingly support such measures.

Days before the election call, Trudeau’s government announced that it would mandate vaccinations for federal civil servants and passengers traveling domestically on planes and trains. Conservative Party leader Erin O’Toole has said that he encourages vaccinations and wants to get Canada’s vaccination rate above 90 percent. But he would not mandate them for federal workers, instead requiring unvaccinated government workers to be tested daily.

Canada has one of the highest immunization rates in the Group of 20 nations. Nearly 74 percent of people have received at least one dose of a coronavirus vaccine and about 68 percent are fully vaccinated, according to Our World in Data, which tracks publicly available figures.

Protesters opposed to public health measures have dogged Trudeau on the campaign trail. One of Trudeau’s events in Bolton, Ontario, was canceled last month after officials decided that the demonstrators posed a security threat.

“We all had a difficult year,” Trudeau told reporters after the event was canceled. “Those folks out protesting, they had a difficult year, too, and I know and I hear the anger, the frustration, perhaps the fear. … We need to meet that anger with compassion.”

On Monday, he said that he wouldn’t back down.

“There is a small fringe element in this country that is angry, that doesn’t believe in science, that is lashing out with racist, misogynistic attacks,” Trudeau said at an event in Welland, Ontario.

“Canadians, the vast majority of Canadians are not represented by them,” he added. “And I know [they] will not allow those voices … those anti-vaxxer mobs, to dictate how this country gets through this pandemic.”

O’Toole said in a tweet that the actions of the protesters were “disgusting” and that he condemned them “in the strongest terms possible.”

“Political violence is never justified and our media must be free from intimidation, harassment and violence,” he said.

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Several provinces — including Ontario, Canada’s most populous — have also implemented or announced plans to implement certification programs that would require people to show proof of vaccination to enter public spaces such as restaurants and theaters.

Angry crowds rallying against coronavirus vaccinations have in recent weeks gathered outside hospitals in several Canadian cities and at the home of Ontario’s education minister.

The protesters have been organizing on social media and on apps such as Telegram, where they have been sharing information about Trudeau’s itinerary. In recent weeks, the Liberal Party has removed the exact addresses of his campaign stops from the itinerary made available to the public.

The Royal Canadian Mounted Police and London Police Service did not immediately respond to a request for comment.

Pietsch reported from Seoul.

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