Local people said 21 had died while railway officials put the toll at 13 from the early morning crash on tracks outside the town of Mathura, 50km north of Agra in northern India.

Rescuers, working with mechanical cutters amid a huge crowd of onlookers, battled to free people trapped in a badly mangled carriage that bore the brunt of the collision.

The engine of one train had rammed inside the last carriage of a train in front, reserved for the disabled and luggage. Bloodied bodies and people were pulled from the wreckage before being ferried to local hospitals.

Local railway manager Rajendra Dutt Tripathi said 13 were dead and 22 injured.

A train from the southern state of Goa heading to New Delhi had run into the back of the stationary Mewar Express, an overnight service linking the state of Rajasthan with the capital, he explained.

Tripathi said initial reports suggested the Mewar Express was at standstill because a passenger had pulled the emergency chain and the driver of the Goa express had overlooked a signal requesting him to stop.

Tripathi said stranded passengers from the trains were being shifted to Delhi and the lines were being cleared. Cranes had been called in to remove two stricken carriages still standing on the tracks.