At least six passengers were killed and more than 50 injured when 12 coaches of a long-distance express train connecting north India with Northeast derailed in Jalpaiguri district on Thursday evening.

The 15633 Bikaner-Guwahati Express derailed at Domohoni, on the left bank of the Teesta river, in Maynaguri block at 5.30pm.

The railway authorities, along with the Bengal administration, began relief and rescue operations, which continued till late into the night.

“Six people have been killed in the accident.... The number of deaths may go up as some passengers are still suspected to be stuck on derailed coaches,” said a railway source.

There was no official word on the cause of the tragedy. A high-level safety inquiry committee was formed in the evening to find out the reasons behind the accident.

The train, which was running late by around two hours, had left the New Jalpaiguri station around 4pm. The accident took place soon after the train had chugged out of the New Domohoni station and was on its way to New Maynaguri station.

The NJP and the New Domohoni stations are 42km apart. The railway sources said while 12 coaches had jumped off the tracks, some other compartments got mounted over each other. Video footage from the accident site showed rescue workers struggling to extricate passengers from the coaches.

“There were 1,053 passengers on board at the time of the accident,” said an official of Northeast Frontier Railway.

The news of the accident came when Prime Minister Narendra Modi was holding a meeting on the Covid situation in the country with chief ministers, including Mamata Banerjee. A source at Nabanna said Mamata had spoken to Modi about the accident during the meeting. Then, she immediately instructed senior state government officials to assist the railways in the rescue operation.

“Deeply concerned to hear about the tragic accident of the Bikaner-Guwahati Express in Maynaguri. Senior officers of the state government, DM/SP/IG North Bengal are supervising rescue and relief operations. Those injured will receive medical attention, as early as possible (sic),” the chief minister tweeted later.

Sources in the NFR said railway minister Ashwini Vaishnaw, who was on the way to the accident site, had apprised Modi of the rescue operation.

The railway authorities announced an ex-gratia of Rs 5 lakh each for the deceased, Rs 1 lakh each for seriously wounded passengers and Rs 25,000 each for those with minor injuries.

Passengers near the bogies. Telegraph photo

Another train reached the accident spot around 9pm so that other passengers can travel towards Guwahati.

Before Thursday’s incident, the previous major railway accident was the derailment of Hirakhand Express near Kuneru in Vizianagaram, Andhra Pradesh on January 21, 2017. At least 41 people had died in the AP accident.

The latest accident also brought back the memory of the Jnaneshwari Express tragedy of 2010 in Jhargram. At least 150 people were killed in that crash which was a suspected Maoist attack.

Retired railway officials said some problems on the tracks might have led to the derailment. “Preliminary information says the train was not running at a high speed. There had been reports earlier of train accidents where drivers missed signals because of dense fog. That is not the case here as there was enough light when the accident took place. It seems the accident has happened because of some problems on the tracks,” said a former railway official.