India's rail line minister has suggested signal failure prompted the Odisha rail catastrophe, with a "change in electronic interlocking" as the likely cause.

Ashwini Vaishnaw later said the cause and people responsible for the deadly three-train crash in eastern India had been identified but gave no details.

A report into India's most obviously terrible rail mishap this century is due later.

Meanwhile, the death toll has been revised down to 275 after some bodies were counted twice, officials said.

Of the 1,175 harmed individuals taken to medical clinics, 793 have been discharged.

The crash saw a passenger train derail after colliding with a stationary goods train, with another passenger train traveling in the opposite direction then striking derailed carriages.

In railway signalling the electronic interlocking system sets routes for each train in a set area, ensuring the safe movement of trains along the track.

India has one of the largest train networks in the world with millions of passengers using it daily, but a lot of the railway infrastructure needs improving.

Mr. Vaishnaw's comments come after the South Eastern Railway also blamed signal failure. The minister also said one of the mainline tracks had now been restored.

Around 2,000 people are thought to have been on board the two passenger trains involved.

On Saturday Prime Minister Narendra Modi visited the crash scene and vowed that anyone found guilty would be "punished stringently".

The exact sequence of events has been the subject of conflicting accounts.

Officials say several carriages from the Coromandel Express, traveling between Kolkata (formerly Calcutta) and Chennai (formerly Madras), derailed at about 19:00 (13:30 GMT) after hitting a stationary good train. It remains unclear how the Express ended up on the same track as the goods train.

Several of the Coromandel Express's coaches then ended up on the opposite track. Another train traveling in the opposite direction - the Howrah Superfast Express traveling from Yesvantpur to Howrah - collided with derailed carriages.

On Saturday KS Anand, chief public relations officer of the South Eastern Railway, said a preliminary report indicated that the accident was the result of signal failure.

"The Coromandel Express was supposed to travel on the main line, but a signal was given for the loop line instead, and the train rammed into a goods train already parked over there," he said.

Trains in India can get very packed at this time of year, with a growing number of people travelling during school holidays.

The country's worst train disaster was in 1981, when an overcrowded passenger train was blown off the tracks and into a river during a cyclone in Bihar state, killing about 800 people.

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