Onlookers watch as rescuers work after a cargo train rammed into Kanchanjunga Express, a passenger train, near New Jalpaiguri station, West Bengal state, India, on Monday. AP

A goods train smashed into the rear of a passenger train in India's West Bengal state on Monday, killing at least eight people and injuring about 30, a police official said, as rescue teams worked to extricate others feared trapped.

Media showed images of the pile-up, with containers from the goods train strewn on the tracks and one carriage nearly vertical in the air in the accident, which followed another a year ago that was the worst in more than 20 years.

The goods train hit the Kanchanjunga Express, which was on its way to Kolkata, the capital of West Bengal, from the northeastern state of Tripura, causing three carriages of the passenger train to go off the rails.

"So far, five people are dead and we have rescued 25 to 30 injured," Abhishek Roy, a senior police official in the eastern state's district of Darjeeling, where the accident happened, told news agency ANI.

"Their injuries are not fatal. We have rescued them with their luggage."

Railway officials said more people were feared trapped inside the mangled carriages, but there were no immediate details.

Residents of the area heard a loud sound and saw the pile-up when they got to the site, several told ANI, in which Reuters has a minority stake.

Rescuers were tackling the aftermath on a "war footing", Railway Minister Ashwini Vaishnaw said in a post on X.

Chances of a large number of casualties were reduced, however, since two of the three derailed carriages of the express train were laden with goods, said a railway official who spoke on condition of anonymity.

About 288 people died a year ago in India's worst rail crash in more than two decades in the neighbouring state of Odisha, caused by a signal failure.

Reuters