Superintendent of Police Kunal Agarwal said all the three injured were referred to Burdwan Medical College and Hospital with one of them having his arm ripped apart from elbow.
The SP said investigations were on but the three were suspected to be making crude bombs inside a room when the incident took place.
The roof of the room was blown off under the impact of the blast, he said.
To a question, the SP said the three injured were suspected to have criminal antecedents but a clearer picture will emerge as the probe progressed.