Bridge between US, Canada closed following explosion: Sources

The Rainbow Bridge connecting the U.S. and Canada at Niagara Falls, New York, has been closed after a vehicle explosion, according to the FBI and local authorities.

The Niagara Falls mayor's office said the incident involved a vehicle crossing into the U.S. from Canada.

The FBI is at the scene.

Ron Rienas, GM of the Buffalo and Fort Erie Public Bridge Authority, told ABC News all four Canada-U.S. bridges over the Niagara River have been closed out of an abundance of caution while the Rainbow Bridge investigation continues.

New York Gov. Kathy Hochul said, "At my direction, the New York State Police is actively working with the FBI Joint Terrorism Task Force to monitor all points of entry to New York. I am traveling to Buffalo to meet with law enforcement and emergency responders and will update New Yorkers when more information becomes available."

The Buffalo Niagara International Airport said it'll be increasing security, with car checks and additional screenings for travelers.

This is a developing story. Please check back for updates.