Police said Wednesday they have seized about 520 spent artillery shells from the home and shop of a 32-year-old man and a courier distribution center where a shell exploded earlier this week, both in Shizuoka Prefecture.
Norihisa Kotani, 32, a sheet-metal worker from Fuji, Shizuoka Prefecture, is suspected of sending the parcel that exploded Monday night while awaiting transit at a Yamato Transport Co. facility in Susono. The blast injured a part-time worker.
Police sent Kotani to prosecutors Wednesday on suspicion of illegal possession of explosives. Kotani, who was arrested Tuesday, has admitted to the allegations, they said.
The police said the confiscated shells include the kind used in grenade launchers. Kotani sells used army materials through his shop.
Takuya Uchida, a 20-year-old part-time worker at Yamato Transport, was sorting parcels at the center with three other employees when the package, addressed to someone in Aichi Prefecture, exploded at about 9 p.m. Monday.
Uchida suffered lacerations to his face and legs but the injuries are not life-threatening, the police said earlier.
Kotani is also suspected of negligence resulting in injury, police said.
Investigators searched Kotani's house Tuesday and seized shells mostly between 81 mm and 155 mm caliber.
According to the police, Kotani collected artillery shells from locations such as Self-Defense Forces drill sites in Shizuoka Prefecture and sold them via Internet auctions.
He had sent parcels containing shells used in grenade launchers as well as shells used in firing exercises to 11 people in Miyagi, Ibaraki, Gunma, Saitama, Shizuoka, Aichi, Hiroshima and Kagawa prefectures.
Police said labels on most of the parcels falsely indicated they contained garments.
