TORONTO -- Fans at a Toronto Raptors game continued an emerging trend Sunday of booing the American national anthem at pro sporting events in Canada.

Fans of the NBA's lone Canadian franchise booed the anthem after similar reactions broke out Saturday night at NHL games in Ottawa, Ontario, and Calgary, Alberta, hours after U.S. President Donald Trump made his threat of import tariffs on America's northern neighbor a reality.

After initially cheering for the 15-year-old female singer, fans booed throughout "The Star-Spangled Banner" performance. At the end, mixed boos and cheers could be heard before the crowd erupted in applause for the Canadian anthem, "O Canada."

Fans also booed Sunday night when Agasha Mutesasira began her performance of the American national anthem in Vancouver, British Columbia, where the NHL's Canucks hosted the Detroit Red Wings.

Raptors forward Chris Boucher, a Canadian citizen, was asked after his team's win over the LA Clippers whether he'd ever experienced something like that.

"No, no, no," he said. "But have you ever seen us getting taxed like that?"

Trump declared an economic emergency Saturday in order to place taxes of 25% on imports from Canada and Mexico and 10% on imports from China. Energy imported from Canada, including oil, natural gas and electricity, would be taxed at a 10% rate.

Canadian Prime Minister Justin Trudeau and Mexican President Claudia Sheinbaum ordered retaliatory tariffs on goods from America in response.

Joseph Chua, a Toronto resident who was at the game, said he's going to be feeling the tariffs "pretty directly" in his work as an importer.

Still, he said he doesn't think booing is "the right thing to do in this situation." He chose to stay seated instead.

"I have a bunch of American family, friends that live in the states that are Americans, we travel to America all the time, but I thought chanting, 'Canada,' would be a more appropriate stance," said Chua, who was deliberately wearing his red Canada Basketball cap. "Usually I will stand. I've always stood during both anthems. I've taken my hat off to show respect to the American national anthem, but today we're feeling a little bitter about things.

"We were already talking about what businesses are Canadian, specifically, what are American, specifically, what to avoid. When I go grocery shopping, I will definitely be trying to avoid American products and groceries."

U.S. national anthem boos in Canada are rare but not unheard of, especially when tied to world events. In the early 2000s, fans at games in Canada booed to show their disapproval of the U.S.-led war against Iraq.

Clippers star Kawhi Leonard, who won an NBA championship with the Raptors in 2019, and coach Tyronn Lue declined to comment on the booing.

Lue, however, sang along to "O Canada." He said he just likes the song.

"I heard it a lot of times being in the playoffs here, so I know it by heart," he said.