While Canadian government officials were working under the assumption that the car explosion that occurred on Wednesday at the Rainbow Bridge in Niagara Falls was terrorism-related, according to national security sources, American officials now confirm that "there is no indication of a terrorist attack" at this time.

According to a statement from the Buffalo FBI office late Wednesday night: "The Buffalo FBI has concluded its investigation at the Rainbow Bridge incident scene. The search at the scene did not reveal any explosive materials, no terrorism link was identified, and the matter has been transferred to Niagara Falls Police Department as a traffic investigation."

The statement continued, "The FBI thanks our law enforcement partners at the local, state, and federal levels for their assistance, and we remain committed to our mission of keeping the public safe."

Speaking to reporters earlier in the evening, New York Governor Kathy Hochul said, as the investigation continues: "At this time, there is no indication of a terrorist attack."

Hochul said, "Based on my briefings with experienced law enforcement, the FBI, Homeland Security, and Customs and Border Protection... they are still analyzing this, but there is no indication based on any online threats, or anyone claiming credit for anything."

The governor added that she wants to share this preliminary information so as not to "leave the public in more anxiety than they need at this time."

Soon after, US law enforcement officials held a press conference, confirming that there is no indication that the incident is terrorism-related. The special agent in charge of the FBI, Matthew Miralia, said the police have local suspicions in mind and continue to investigate with the Joint Terrorism Task Force, but so far nothing has drawn their attention suggesting "anything of this nature."

Officials now confirm that the vehicle came from the US side of the border, and just after 11:20 AM Eastern Time, after traveling at high speed, it flew through the air and struck the US Customs and Border Patrol booths before catching fire.

Two people in the car that exploded at the incident scene have been declared dead, and officials said a third person, believed to be a border officer, was injured and taken to the hospital but was later released.

Hochul continued, "If you can imagine this car basically burnt out. Nothing remained except the engine. Debris scattered over 13 or 14 booths. So the scene is large, and it will take a lot of time... until we can put it together to get to the 'real story.' It has not been determined if it was an accident, you don’t know if the driver was deliberate in his driving... All I know is there was a horrific accident, collision, explosion, loss of life, but at this time no known terrorism link."

This significant update comes after national security sources told CTV News that although other causes such as a medical event or reckless driver were not ruled out, under the terrorism assumption, officials had alerted police forces and instructed them to increase their presence at potential terrorist targets.

Earlier on Wednesday, Prime Minister Justin Trudeau told the House of Commons that "additional measures" are being considered and activated "at all border crossings across the country."

No Canadian official referred to the latest information from the United States as of 6:30 PM.

Shortly after footage and reports about the suspicious incident appeared, Canadian authorities were in contact with their American counterparts and investigators at the scene.

All relevant security organizations and departments on this side of the border met to discuss the incident, including the Canada Border Services Agency (CBSA), the Royal Canadian Mounted Police (RCMP), and Trudeau's national security and intelligence advisor, according to sources.

While officials were trying early on to determine whether it was an isolated incident and as a result four border crossings between Canada and New York were closed as of Wednesday evening, the Lewiston-Queenston, Peace, and Whirlpool bridges were reopened but the Rainbow Bridge remains closed until the scene is cleared.

Public Safety Minister Dominic LeBlanc said: "We definitely believe that if US authorities consider it safe to reopen the three bridges near the Rainbow Bridge, that apparently indicates an isolated incident."

LeBlanc added in an interview with Power Play with Vassy on CTV News: "But I think it’s important not to speculate or overstate the circumstances. It’s important for us to work with the Americans and get reliable and confirmed information as their investigations continue."

In an interview before the governor's press conference, LeBlanc was asked whether terrorism had been ruled out; the minister said, "It is too early to draw final conclusions on that."

Trudeau was briefed before question period on Wednesday but left early after issuing a statement in the House of Commons to obtain more information.

At that time, Trudeau said: "There are a lot of questions and we are following up to try to get as many answers as possible as quickly as possible. We are in close contact with American officials and will continue to work closely with them." "We will remain engaged and provide updates."

In his initial remarks to the media this afternoon, LeBlanc said the government considers this "a very serious situation," but declined to speculate on the origin or causes of the explosion.

When asked if there is a current threat to Canadians, LeBlanc said national security and public safety officials "are doing everything Canadians expect at this moment to ensure border crossings can operate safely, and that their security is guaranteed."

LeBlanc spoke with US Secretary of Homeland Security Alejandro Mayorkas at noon about cross-border cooperation between Canadian and US security agencies amid growing concern given the location and "violent circumstances."

The Canada Border Services Agency (CBSA) and the Royal Canadian Mounted Police (RCMP) also issued statements regarding the situation, with the national police force providing little beyond saying it is working with its local and international partners, and the CBSA noting that the FBI was leading the investigation.

Both Conservative Leader Pierre Poilievre and New Democratic Party Leader Jagmeet Singh expressed early concerns about the safety of Canadians and those affected, while calling on Canada to provide resources to aid the investigation and keep Canadians informed.

Conservative MP for Niagara Falls, Tony Baldinelli, said the images of the explosion were "shocking" and he was thinking of his border community.

He said, "It’s a binational community. We all have friends and family on both sides. So when something like this happens, it hurts us all because we are so closely interconnected."