Fans at Scotiabank Arena loudly booed during the American national anthem before the Toronto Raptors hosted the Los Angeles Clippers on Sunday.

They then switched to loud cheers when “O Canada” began.

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

The strong reactions to both national anthems was likely in response to a mounting trade war between Canada and the United States.

‘We’re feeling a little bitter’

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.”

Fans also sang along with 15-year-old Kyra Daniel when she began the Canadian national anthem.

L.A. head coach Tyronn Lue actually sang the Canadian national anthem in full, but said he had no reaction when the American anthem was booed.

“I like that song. I heard it a lot during the playoffs,” Lue said. “I know it by heart.”

Raptors head coach Darko Rajakovic had no comment on the boos.

Clippers superstar Kawhi Leonard, who helped Toronto win the 2019 NBA championship, got a warm round of applause when he was introduced before tipoff.

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

Prime Minister Justin Trudeau and Mexico’s president ordered retaliatory tariffs on goods from the U.S. in response.

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.

The NHL’s Canucks will host the Detroit Red Wings on Sunday night in Vancouver.

The Raptors are the most recent Canadian team to win a major professional championship. The Toronto Blue Jays’ World Series win in 1993 was the previous major title won by a franchise based in Canada.