Amtrak said it had initiated its "Incident Response Team" and sent emergency personnel to the scene to assist local authorities in the evacuation effort. (Representative image)
At least three people were killed and multiple others injured when a US train derailed on September 25, rail operator Amtrak said, with rescuers rushing to safely evacuate all passengers and crew.
Approximately 141 passengers and 16 crew members were on board when eight train carriages -- travelling from Chicago to Seattle -- came off the tracks at around 4 pm (2200 GMT) in northern Montana.
"We are deeply saddened to learn local authorities are now confirming that three people have lost their lives as a result of this accident," the firm said, adding that there were also "reported injuries" among those traveling on the train.
The three deaths were confirmed by the local Sheriff's Department, ABC News reported, but authorities did not say how many people were injured.
It was not immediately clear what caused the incident.
Footage posted on social media showed people waiting by the tracks, luggage strewn next to them, with train carriages seen listing off the rails and at least one toppled onto its side.
The government's National Transportation and Safety Board said on Twitter that it was launching a "go-team to investigate" the derailment.
Amtrak said it had initiated its "Incident Response Team" and sent emergency personnel to the scene to assist local authorities in the evacuation effort.
Montana's Disaster and Emergency Services coordinator Amanda Frickel told the New York Times that "well over 50 people had been injured".
She said teams of rescuers were at the scene and multiple hospitals -- as well as medical helicopters -- were on standby.
Authorities were not releasing further details for the time being, she said, adding: "Everybody who is alive has been extricated from the wreck."
The Empire Builder train derailed in a remote area near Joplin, Montana, a town of around 200 people near the border with Canada.
The US rail network suffers from chronic underfunding and fatal accidents sometimes occur.
In 2018, two people died in South Carolina when an Amtrak train traveling on the wrong tracks collided with a stationary freight train, in a crash later blamed on safety oversights.
A year earlier, an Amtrak passenger train traveling on a new route for the first time derailed in Washington state, killing at least three people as cars plunged off a bridge onto a busy highway at the height of morning rush hour.