The cause of one of India's deadliest train crashes was signal error coupled with a fault in the interlocking safety system, the railway minister said according to local media reports on Sunday.
"The setting of the point machine was changed. How and why it was done will be revealed in the probe report," the minister, Ashwini Vaishnaw, was quoted by the Press Trust of India as saying.
The death toll from Friday's crash has been revised down from 288 to 275, the government of eastern Odisha state has said after it found some bodies had been counted twice, according to the news agency.
The state government said 187 bodies have yet to be identified and they are being stored at local facilities.
Nearly 1,200 people were injured after a passenger train entered the wrong track, hit a freight train, derailed and collided with another passenger train passing in the opposite direction near Balasore in Odisha.