A speeding car crashed and exploded in a deadly fireball on a US-Canada border bridge, triggering a major security scare on the eve of Thanksgiving.
Two people in the vehicle died, and a US border agent was injured, but New York's governor ruled out terrorism.
The car was being driven from the New York side of the border to Rainbow Bridge when it crashed at a checkpoint.
The incident near Niagara Falls saw the closure of four bridges on the world's longest international border.
The explosion happened at around 11:30 local time (16:30 GMT) on Wednesday, causing serious disruption on one of the busiest travel days of the year, the eve of the Thanksgiving holiday in the US.
Train services between New York and Canada were temporarily halted and officers at Buffalo and Niagara Falls airports went into a heightened state of alert screening cars for explosives.
The incident stoked fears of a possible terror attack, and baseless speculation swirled online about a supposed threat to the Macy's Thanksgiving Day Parade in New York City.
Both US President Joe Biden, who is in Massachusetts for Thanksgiving, and Canada's Prime Minister Justin Trudeau were quickly briefed on the incident.
Mr Trudeau excused himself from Question Period in the House of Commons, and said his government was taking the incident "extraordinarily seriously".
As a precaution, officials used trucks to block the Canadian entrance to Rainbow Bridge, which links Ontario with New York and the US city of Niagara Falls with Niagara Falls, Canada.
Several hours after the blast, there was relief when New York Governor Kathy Hochul told reporters: "Based on what we know at this moment, there is no sign of terrorist activity with respect to this crash."
She added that one of the people who died was a "local" from the western New York region.
The two who died were a married couple - the husband was driving and his wife was the passenger, US law enforcement officials said.
According to CNN, the motorist was driving a 2022 Bentley and had just been to a US casino after a concert by hard rock band Kiss that he was initially going to attend in Canada had been cancelled.
The car travelled at a "very high rate of speed", the governor said, hurtling over an 8ft (2.4m) fence, though it was unclear if the crash was deliberate.
The vehicle had been "incinerated" and nothing was left but the engine, she said. Not even a registration plate was recovered.
Governor Hochul said video of the crash was "surreal" and looked almost like it "was generated by AI".
The person who sustained non-life threatening injuries in the crash is a US Customs and Border Protection (CBP) officer, she added.
The governor noted it was fortunate that more people were not hurt at the busy crossing "when you look at the scale of the scene, how far the pieces of this vehicle exploded and scattered".
Rainbow Bridge remained closed on Wednesday night, but three other US-Canada crossings - the Peace Bridge, Lewiston-Queenston Bridge and Whirlpool Bridge - had reopened to the public.
Toronto resident and eyewitness Dor Tamang told OceanNewsUK he was on the second floor of a CBP building when the blast occurred.
Mr Tamang said he felt the ground shake inside the building.
Another eyewitness told the OceanNewsUK: "We just saw this car going up in flames." He said the blast felt like a "mini-earthquake".
Aaron Beatty, from Cleveland, Ohio, said he crossed into Canada to see Niagara Falls on Wednesday morning.
"I said, 'oh, I'll just cross over to the Canadian side for a quick hour to see the other side and walk back," Mr Beatty told the OceanNewsUK.
But as he was heading back into the US, a border agent told him to go back to Canada.
"That one hour turned into almost eight hours now," Mr Beatty said.
