The bombs were inserted into the handle of mosquito bats and could be triggered using remote control device, police said, adding, they were later defused.
Police are on the lookout for five others, who are absconding.
Cases had been registered against nine persons for making the crude bombs and storing them, they said.
The seizure was made from Pattalakunnu area in Mannuthy following information provided by two persons who were arrested earlier in connection with an assault on a person recently, sources said, adding, an improvised dynamo was also recovered. The explosives were concealed in crevices of rocks in the area.