This post originally appeared at https://www.wisconsinrightnow.com/multiple-border-crossings-closed-by-possible-terror-attack/

Multiple border crossings are closed and two are dead after a vehicle explosion Wednesday on the Niagara Falls Rainbow Bridge connecting Canada and the United States.

Multiple reports say law enforcement sources are investigating as a possible terrorist attack. The explosion occurred at or near a toll checkpoint, the car was traveling at a high rate of speed, and both occupants in the vehicle were killed.

The afternoon before Thanksgiving Day, all four border crossings in western New York were closed.

No motive was immediately conveyed by federal or state authorities. There were no other reports of additional injuries on the bridge or surrounding area. It is unclear what precipitated the explosion.

The FBI confirmed the explosion and coordinated the investigation with state and local lawmen.

“The FBI Buffalo Field Office is investigating a vehicle explosion at the Rainbow Bridge, a border crossing between the U.S. and Canada in Niagara Falls,” the FBI said in a release. “The FBI is coordinating with our local, state and federal law enforcement partners in this investigation. As this situation is very fluid, that all we can say at this time.”

New York Gov. Kathy Hochul, posting on social media, said state police and the FBI Joint Terrorism Task Force was working “to monitor all points of entry to New York.”

Hochul, in another social media post, wrote, “I have been briefed on the incident on the Rainbow Bridge in Niagara Falls and we are closely monitoring the situation. State agencies are on site and ready to assist.”

The explosion came at one of the nation’s busiest travel times.

“Cars coming into the Buffalo Airport will undergo security checks and travelers can expect additional screenings,” said a statement from the Buffalo Niagara International Airport.

President Joe Biden is vacationing in Nantucket, Mass. A White House statement said the administration was “closely monitoring” the situation.

Canadian Prime Minister Justin Trudeau briefly commented on the incident in Parliament, saying, “This is obviously a very serious situation in Niagara Falls.” He excused himself from a Question Period in the House of Commons while being briefed on the attempted attack.