India's railway minister says a multiple-train crash in the east of the country on Friday was caused by a problem related to an operation system.

Local authorities said on Sunday that the accident in the state of Odisha left 275 people dead and more than 1,100 others injured. They said nearly 800 of the injured have left the hospital. The numbers were revised from earlier reports of 288 deaths and about 900 injuries.

Railway Minister Ashwini Vaishnaw spoke about the crash in an interview with a local media outlet on Sunday.

He said the accident happened due to a change that occurred during electronic interlocking. The computerized interlocking system is used to switch signals and tracks. The minister did not explain what kind of change triggered the accident.

The railway board under the minister said at a news conference that investigations so far indicate there was some kind of signaling problem.

The board explained that an express train traveling to the southern city of Chennai did not enter the main track and instead went into a loop line for some reason. The board said the train collided with a stationary freight train there at a speed of 128 kilometers per hour and derailed. Some of the derailed carriages then hit the rear part of another express train.

The crash took place on a key train line connecting major cities in India's east and south.

Prime Minister Narendra Modi's government aims to quickly restore service to prevent public discontent from growing ahead of next year's general election.