Home Minister P Chidambaram said on Friday that the train derailment in West Midnapore appeared to be an act of sabotage but it was not yet clear whether explosives were used to blast the tracks.
"It appears to be a case of sabotage where a portion of the railway track was removed.
Whether explosives were used is not yet clear," he said in a statement here.
Chidambaram said the National Disaster Response Force (NDRF) has deployed four teams to assist rail authorities in relief operations.
"A total of 132 personnel with necessary equipment have reached the site of the tragedy and are assisting the state government and railway authorities," he said.
The Minister said he was deeply saddened by the tragedy that struck the Howrah-Kurla Gyaneshwari Express in West Midnapoore district Friday morning.
"Convey my sincere and heartfelt condolences to the family of the deceased. I offer my sympathies to the injured," he said.
Chidambaram said every effort was being made to rush the injured to hospital for treatment and helicopters have been pressed into service for the purpose.
Sixty-five passengers of a Mumbai-bound Gyaneshwari Express were killed early Friday and 200 injured in a suspected Maoist attack which led to derailment of 13 coaches, five of which were were hit by a goods train coming from the opposite direction.