Maoists were suspected for the blast, which disrupted train services on the Mumbai-Howrah route for some time.
According to police, no one was hurt in the incident which triggered panic in the locality.
As the culvert was close to the railway tracks, the station master and other staff of nearby Bhalulata station thought it was an attack on the railway lines and alerted police.
However, train services resumed after the security personnel gave clearance.
The police suspected that Maoists' action was in revenge to arrest of six ultras belonging to Jheripani village on Aug 3.