There was, however, no report of any casualty or injury, police said.
The abandoned canteen was inside the Sripur colliery beside a school in Jamuria under Asansol police station, they said.
The blast took place shortly after 10.30 AM when the school was open.
Local people informed the police and four bombs were found in the canteen, police said, adding, the cause behind the explosion is being investigated.