LUCKNOW, India: The death toll from a train accident in northern India has risen to 53, a senior police official said Monday, with a Swedish man reportedly among the dead.

“The rescue operations are now over. Fifty-three bodies have been retrieved and 249 are injured, many of whom are still in the local hospitals,” Brij Lal, a senior police official from the northern state of Uttar Pradesh, told AFP.

The Press Trust of India news agency said a Swedish man was among the dead.

Police official Ram Bharose told PTI that another Swede was reported to be missing after the accident, which occurred when a packed train travelling at full speed derailed Sunday, killing 53 passengers as carriages were forced on top of each other.

Rescue teams and local residents worked frantically overnight, trying to cut through the twisted metal carriages to free people trapped inside.

The Kalka Mail was heading from Howrah, the main station for the eastern city of Kolkata, across India to the capital New Delhi when it sped off the tracks.

Officials said the death toll could rise and that an investigation had been launched.

Railway Board Chairman Vinay Mittal told PTI Monday that preliminary investigations had shown that the signals and the tracks were functioning normally prior to the accident.

Late Sunday, an explosion hit another train in the northeastern state of Assam, but police were unable to say whether the blast was caused by separatist militants active in the area.

No fatalities were reported in that incident but 20 of the 100 injured were described by police as being in a serious condition.

The Guwahati-Puri Express was nearing Ghograpara, about 70 kilometres (44 miles) from Assam's main city of Guwahati, when the blast struck.

Militants from both the outlawed United Liberation Front of Asom (ULFA) and the National Democratic Front of Bodoland (NDFB) are active in the region, but the cause of the explosion was not immediately known.

Last week 38 people were killed in a rail crash in Uttar Pradesh when a train slammed into a bus carrying a wedding party.

India's state-run railway system - still the main form of long-distance travel despite fierce competition from new private airlines - carries 18.5 million people daily.

The worst accident in India was in 1981 when a train plunged into a river in the eastern state of Bihar, killing an estimated 800 people.

The railway is the country's largest employer with 1.4 million people on its payroll and it runs 11,000 trains a day.

Experts say the creaking system, the world's second largest under a single management, is desperately in need of new investment to improve safety and help end transportation bottlenecks that threaten the country's economic growth.