The raid was carried out by a joint squad of CRPF and state police in the Bamdevpur village under Rampurhat police station area in the district.
The operation was based on intelligence inputs and the forces recovered 105 country-made bombs, 1kg of gunpowder, sharpnels and other explosive material, a senior official said.
The cache has been handed over to local police and further investigation were on, the official said.
Birbhum goes to polls on April 30 along with eight other constituencies in West Bengal.