Seven people have been killed and at least 12 injured after a commuter train struck a car north of New York City.

A Metro-North Railroad spokesman said the northbound train struck the vehicle at a railway crossing in Valhalla.

The vehicle and the front carriage of the train caught fire.

The railroad crossing gates had come down on top of the SUV, which was stopped on the tracks, the Metropolitan Transportation Authority said.

The driver got out to look at the rear of the vehicle, then she got back in and drove forward, but was struck and killed.

In the Metro-North Railroad's deadliest crash, six passengers of the train were also killed after flames ripped through the carriage.

"This is a truly ugly and brutal site," Governor Andrew Cuomo said at the scene of the crash 32km north of New York City.

More than 750 passengers are thought to have been aboard the train, including commuter Justin Kaback.

"I was trapped," he told ABC News.

"You know there was people in front of me and behind me, and I was trapped in the middle of a car and it was getting very hot.

"All the air was turned off so there was no circulation so it was definitely scary especially when people are walking by on the outside and they said, 'The train's on fire. There's a fire.'"

Another passenger told reporters he was sitting near the back of the train when he felt a "small jolt".

Neil Rader said: "It felt not even like a short stop, and then the train just completely stopped."

He said frantic passengers had to evacuate by breaking glass on the doors to get out, and that he saw 50 to 60 ambulances at the scene.

"I've never seen anything quite like it," he added.

Jamie Wallace was also on the train:

Around 400 of the passengers who evacuated the train were taken to a local rock climbing gym for shelter. Buses were sent to the centre to pick them up and take them to their destinations.

Metro-North is the nation's second-busiest railroad, after the Long Island Rail Road.

It was formed in 1983 and serves around 280,000 passengers a day in New York and Connecticut. Service on a portion of its Harlem Line was suspended after the crash.

Originally posted at 7.33am