India's Railways Minister Ashwini Vishnaw has identified the cause of the worst train accident in decades, as well as those responsible.
"We have identified the cause of the accident and the people responsible," the railway minister told the Indian News Agency, adding that it was "inappropriate" to give details before the final report of the investigation.
At least 288 people were killed and about 900 injured in Friday's incident near the town of Palasur in the eastern Indian state of Odisha.
"The change occurred during the electronic entanglement, and the accident occurred because of that," Vishnaw said, referring to a complex signaling system designed to prevent trains from colliding by regulating their movement on the tracks.
"Whoever did it and how it happened will be found after a proper investigation."
According to Indian Railways, its network transports more than 13 million people every day, but its safety record is uneven due to the aging of its infrastructure.
Local newspapers reported that "human error" in regulating traffic lights could have caused the collision. According to the report, the Kurumanda Express, which connects Calcutta and Madras, was given the green light to run on the main track, but its route was changed due to human error to a track used by a freight train.
The passenger train collided at a speed of about 130 kilometers per hour with the freight train, causing three carriages to overturn on the adjacent track and collide with the back of an express train that was on a journey between Bangalore and Kolkata that was on site.
Indian authorities have announced that the family of each dead person will receive compensation of 12 million rupees ($200,50), the seriously injured will receive <>,<> rupees and the lightly injured will receive <>,<> rupees.
India's deadliest train accident occurred in 1981 when a train crashed off a bridge into a river in Bihar, killing nearly 800 people.