Canadian Prime Minister Justin Trudeau wore a bulletproof vest onstage Saturday night as he delivered a speech amid heavy security after authorities learned of a security threat, according to reports.

Trudeau, leader of the nation’s Liberal Party, is seeking reelection Oct. 21. He addressed an audience of about 2,000 supporters in Mississauga, Ontario, just outside Toronto, the CBC reported.

Liberal officials would not disclose the nature of the security threat, but the event was delayed for about 90 minutes, according to the Toronto Star. The Royal Canadian Mounted Police also would not comment.

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The prime minister’s wife, Sophie Gregoire Trudeau, did not introduce him to the audience, as was originally planned, the CBC reported.

When he finished speaking, Trudeau mingled with some members of the crowd before leaving.

No unusual incidents occurred during Trudeau’s appearance, according to the CBC.

Trudeau’s security detail was more numerous than usual, the CBC reported. Two weeks ago, a protester at a climate change event in Montreal was arrested after approaching Trudeau.

Leaders of the rival Conservative Party and New Democratic Party expressed concern for Trudeau’s safety.

Conservative Leader Andrew Scheer wrote on Twitter:

Very upsetting to hear that Justin Trudeau had to wear a bulletproof vest tonight at a campaign event. Threats of violence against political leaders have absolutely no place in our democracy. Thank you to the RCMP for taking these threats seriously and keeping us safe,” he wrote.

New Democratic leader Jagmeet Singh posted the following:

“Any threat made against @JustinTrudeau, or any leader, is troubling to all of us,” he wrote. “No matter how you vote or believe, no one should face threats of violence. To the officers who protect all of us – thank you.”

On Wednesday, Trudeau had an awkward exchange with some schoolchildren, who asked him about a past incident in which he darkened his skin as part of a party costume.

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"Why did you paint your face brown?" a girl asked.

"Ooh, it was something I shouldn't have done because it hurt people," he said. "It's not something that you should do and that is something that I learned. I didn't know it back then but I know it now -- and I'm sorry I hurt people."

Trudeau apologized last month for wearing brownface makeup to an "Arabian Nights" party at the private school where he was teaching in 2001, saying, "I should have known better."

Fox News' Sam Dorman contributed to this report.