Two passengers are reported dead after a vehicle exploded near the Rainbow Bridge border crossing separating the United States from Canada.

The vehicle contained explosives and the incident is being investigated as a suspected terrorist attack, law-enforcement sources told Fox News. A border agent was also reportedly injured in the attack.

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

The Rainbow Bridge border crossing, which connects Niagara Falls N.Y., to Niagara Falls, Canada, has been closed, as have all other border crossings in the area.

The slain passengers were reportedly traveling from America to Canada.