New York: Border crossings between the US and Canada near Niagara Falls were shut down on Wednesday following a vehicle explosion at Rainbow Bridge, prompting actions by terrorism investigators, media reports said.

According to US media, two people were killed in the explosion, but their identities have not been ascertained till now.

While the cause of the incident was not immediately apparent, New York Governor Kathy Hochul stated that state police and the FBI Joint Terrorism Task Force were overseeing all entry points into the state.

Citing law enforcement sources, the US media reported that there were two passengers in the car.

The vehicle had undergone an initial border checkpoint inspection, after which it was sent for a secondary check.

But the car accelerated, collided with a barrier, and exploded.

The sources underscored that it remained uncertain whether the explosion was caused by a device, AFP reported.

"I am traveling to Buffalo to meet with law enforcement and emergency responders and will update New Yorkers when more information becomes available," Hochul posted on social media.

The office of Canadian Prime Minister Justin Trudeau stated that he had been briefed and was in contact with US law enforcement. The statement said that various Canadian agencies were providing support for the investigation.

Witnesses described hearing a loud explosion and a huge cloud of smoke near the inspection station, according to the report.