Fans at the United States and Canada hockey game in Montreal booed during the U.S. national anthem, and three fights exploded in the first nine seconds of the game.

It’s the first time a fight has broken out at an international hockey tournament since 2004, but it also comes at a time of strained relations between the two countries, The Washington Post reported.

The sold-out crowd at the Bell Centre in Montreal booed during the U.S. national anthem, and the string of brawls broke out.

The game announcer asked both in French and English for fans to “kindly respect the anthems and the players” of each country, the Post noted.

Earlier this month, Canadian fans also booed at the U.S. national anthem in a protest move against President Trump’s plan to impose tariffs on the neighboring country.

Trump and Canadian Prime Minister Justin Trudeau agreed to hold the tariffs for a month in exchange for Canada helping to secure the northern U.S. border to combat the flow of fentanyl into the country.

Canadian officials have noted how displeased its citizens are with the plan, especially after Trump reiterated his desire to acquire the country and turn it into the 51st U.S. state.