The Indian Railways said sabotage by suspected Maoist guerrillas may have caused the train derailment in West Bengal that left 20 people dead and over 100 injured early Friday.
"We suspect it is a case of sabotage. The driver (of the passenger train) has reported to have heard a large sound. There was definite tinkering with the tracks," member railway board Vivek Sahai told reporters here.
The engine and 13 coaches of a Mumbai-bound passenger train derailed and were hit by a speeding goods train in West Bengal early Friday.
Sahai said 20 passengers were dead and 104 injured.
He said Maoists were observing black week since past midnight.
"We had issued a red alert," he said.
Sahai said the deaths were mainly caused by the goods train hitting the three derailed coachs of the Howrah-Kurla Gyaneshwari Super Deluxe Express.
"There have been earlier cases of sabotage but never of this scale," the railway board member said.