Kolkata, April 26 : The NIA is all set to submit a charge sheet on Wednesday in a special court here on the recovery of 81,000 detonators from West Bengal's Birbhum district last year. Sources aware of the development said that a total of eight persons might be named in the charge sheet. The charge sheet is being filed within 90 days since the National Investigation Agency (NIA) sleuths took up the investigation. As many 81,000 detonators were recovered from a passenger- van in the Muhammadbazar area of Birbhum district on June 30, 2022. The detonators were seized by the sleuths of the Special Task Force (STF) of state police. Three persons were also arrested by the STF, the first from Raniganj area in West Burdwan district and the other two from Dhuliyan area in Murshidabad district. The NIA took charge of the investigation on September 29 of the same year. Later the NIA sleuths also arrested two other persons. It is learnt that the use of detonators is quite common in pockets of Birbhum, which houses a number of stone quarries. The detonators are used to blast stone blocks in the area for the purpose of use in stone quarries. However, this was the first time that detonators of such a huge quantity were recovered from the district. This made the investigation sleuths doubt that such a huge quantity could have some other purpose. /IANS