NEW DELHI, India (AP) — A signal error that sent a train down the wrong tracks was to blame for a train derailment in eastern India that killed nearly 300 people and injured hundreds more, authorities said Sunday. .

The probable cause of the deadly accident arose as families from across India rushed to the scene for news of missing loved ones as rescuers combed through the shattered remains of overturned train carriages.

Authorities also rushed to restore train service as the disaster raised new concerns about safety and modernization in the world’s most populous country, where the rail network serves as a lifeline.

Railway Minister Ashwini Vaishnaw said an error in the electronic signaling system caused the train to mistakenly change tracks, leading to Friday night’s accident. Authorities reduced the death toll on Sunday to at least 275 people and said about 400 remained hospitalized with injuries.

«The change in electronic interlocking caused this accident and who did it and what are the reasons will be known after the investigation,» Vaishnaw said in an interview with India’s ANI news agency at the disaster site on Sunday.

A preliminary report signed by rail officials and obtained by NBC News found that the high-speed Coromandel Express was given a signal to enter the main track, but that signal was later removed. The train then entered another line, known as the loop line, and collided with a freight train parked there.

The incoming Yesvantpur-Howrah Express then crashed into the overturned carriages that had overturned on the main line and also derailed, according to the report.

Officials displayed photos of the victims for relatives to identify the bodies at a business park used as a temporary mortuary near Balasore, in the eastern state of Odisha. PUNIT PARANJPE/AFP – Getty Images

Indian Prime Minister Narendra Modi praised the citizens who «plunged» into helping rescue operations when he visited the disaster site on Saturday.

Modi said the government would do everything possible to help those who suffered from the accident and strictly punish those responsible.

The derailment has raised new questions about Modi’s effort to upgrade and modernize a British colonial-era rail network that still suffers fatal accidents. The government has spent billions in an effort to make India’s railway 100% electric by 2024, the same year it faces elections.

Previous train accidents have been attributed to human error or the use of outdated signaling equipment.

In November 2016, more than 100 people were killed when 14 carriages of a passenger train skidded off the track in the north of the country.

India’s worst rail accident so far occurred in August 1995, when two trains collided near New Delhi, killing 358 people.

Modi has been invited to address a joint session of Congress during an official state visit to the United States later this year.

President Joe Biden said in a statement Saturday night that «Jill and I are heartbroken by the tragic news of the deadly train accident in India.» He added: «Our prayers are with those who have lost loved ones and the many who suffered injuries in this terrible incident.»

Ravi Mishra reported from New Delhi and Leila Sackur from London.