According to preliminary investigations, fishplates were found missing from the track where the Kurla-bound Gyaneshwari Express derailed and collided into a goods train on Friday.
Maoists have been suspected behind the attack. The removal of fishplates may have led to the derailment of 13 bogies.
There have reports that there had also been a blast at the site, however this is yet to be confirmed.
The fishplates were removed at the spot where the Mumbai-bound Gyaneswari Express had derailed, a senior police official said.
Inspector General of Police (Law and Order) Surojit Karpurokayastha said that according to preliminary investigation, fishplates were found removed at the derailment site.
Earlier, Railway Minister Mamata Banerjee said the derailment took place after a blast.