TORONTO — Prime Minister Justin Trudeau's campaign moved to contain a growing scandal Thursday after a yearbook photo surfaced of him in brownface at a 2001 costume party and two other similar incidents also came to light.

With the election a month away, he apologized and begged Canadians to forgive him.

Time magazine published the photo on Wednesday, saying it was taken from the yearbook from the West Point Grey Academy, a private school in British Columbia where Trudeau worked as a teacher before entering politics. It shows the then-29-year-old Trudeau in a turban and robe with dark makeup on his hands, face and neck.

Trudeau, who launched his re-election campaign a week ago, said he should have known better.

"I'm pissed off at myself. I'm disappointed in myself," he told reporters on his campaign plane.

He is the latest in a string of politicians to get in trouble over racially offensive photos and actions from their younger days.

Earlier this year, Virginia Gov. Ralph Northam faced intense pressure to resign after a racist picture surfaced from his 1984 medical school yearbook page. He denied being in the picture but admitted wearing blackface as a young man while portraying Michael Jackson at a dance party in the 1980s. Since then, Virginia Attorney General Mark Herring has acknowledged wearing blackface in college, and Alabama Gov. Kay Ivey has apologized donning blackface during a college skit more than 50 years ago. None has resigned.

The photo of Trudeau was taken at the school's annual dinner, which had an "Arabian Nights" theme that year, Trudeau said, adding that he was dressed as a character from "Aladdin."

The prime minister said it was not the first time he darkened his face. He said he once did it while performing a version of Harry Belafonte's "Banana Boat Song (Day-O)" during a talent show.

"I should have known better then, but I didn't, and I am deeply sorry for it," Trudeau said. "I'm going to ask Canadians to forgive me for what I did. I shouldn't have done that. I take responsibility for it. It was a dumb thing to do."

Global News also reported on a third instance, broadcasting a brief video of Trudeau in blackface while raising his hands in the air and sticking out his tongue. The Canadian TV network said it was not clear when and where the tape was made.

The furor could spell more trouble for Trudeau, who polls say is facing a serious challenge from Conservative leader Andrew Scheer in the Oct. 21 election.

The prime minister champions diversity, and multiculturalism and immigration and has been admired by liberals around the world for his policies in the Trump era, with Canada accepting more refugees than the U.S. His Liberal government has also strongly advocated free trade and has legalized cannabis.

But the 47-year-old son of late Prime Minister Pierre Trudeau was already vulnerable following one of the biggest scandals in Canadian political history, which arose when Trudeau's former attorney general said he improperly pressured her to halt the prosecution of a company in Quebec. Trudeau has said he was standing up for jobs, but the scandal rocked the government and led to resignations and a drop in his ratings earlier this year.

His quick apology for the yearbook photo did not stem the criticism from political opponents.

"It is insulting. Any time we hear examples of brownface or blackface it's making a mockery of someone for what they live, for what their lived experiences are. I think he has to answer for it," said Leftist New Democrat leader Jagmeet Singh, a Sikh who wears a turban.

Scheer, the opposition Conservative leader, said brownface was racist in 2001 and is racist in 2019.

"What Canadians saw this evening was someone with a complete lack of judgment and integrity and someone who is not fit to govern this country," Scheer said.

Robert Bothwell, a professor of Canadian history and international relations at the University of Toronto, said he was "gobsmacked" by the development.

"We'll just have to see how the party reacts," he said. "I'm very curious to know how Liberal members of Parliament that are black will react."

He added: "The case has never been conclusively made that Justin is a person of substance. I mean, he may well be. But that impression is just not out there."

Nelson Wiseman, a political science professor at the University of Toronto, said he doesn't believe the photo will cause people to vote differently. Wiseman said race and blackface play a much bigger role in U.S. politics than in Canada.

"This is not the type of scandal that will drive voters to the Conservatives," he said.