The National Investigation Agency (NIA) on Wednesday filed its first supplementary chargesheet in connection with the seizure of a huge cache of detonators and explosives in Birbhum district in April this year. “This takes the total number of accused chargesheeted in the case to seven. Five persons were named in the original chargesheet filed in April this year. The NIA on Wednesday also raided illegal godowns at two locations in Birbhum district in connection with the same case. The godowns were being run by another suspect in the case, identified as Manoj Ghosh. The agency has seized ammonium nitrate, country-made pistol, live ammunition, gelatin sticks and incriminating documents in these raids,” an NIA spokesperson said.