Vehicle Explosion Shuts Down U.S.-Canada Bridge in Niagara Falls

“As the situation is very fluid, that’s all we can say at this time,” the post said.

The White House said that it was closely monitoring the situation and that President Biden and Attorney General Merrick Garland had been briefed.

Gov. Kathy Hochul of New York said that “state agencies are on site and ready to assist.” The New York State Police are working with the F.B.I. to monitor all points of entry to New York, Ms. Hochul said.

In Canada, Prime Minister Justin Trudeau told the House of Commons, “We are taking this extremely seriously,” in brief comments before he left for an update on the situation.

Dominic LeBlanc, the nation’s public safety minister, declined to say whether the vehicle that exploded had come from Canada because the government law enforcement agencies had received contradictory information.

“This is a rapidly changing situation,” he told reporters. “All measures are being taken to ensure that people will be safe.”

He said that at the request of American officials, all four bridges between Canada and the United States in the Niagara area have been closed, including the Rainbow Bridge, Peace Bridge, Lewiston-Queenston Bridge and Whirlpool Bridge.

Paul Lane contributed reporting from Niagara Falls. Glenn Thrush contributed reporting from Washington.