A member of the Ground Self-Defense Force (GSDF) was killed Thursday after being struck by shrapnel from a grenade that exploded during a drill in Yamanashi Prefecture.
The member killed was Taku Yamamiya, a 29-year-old sergeant who belonged to a unit at Camp Nerima in Tokyo.
He was taken to a hospital following the explosion, where he was confirmed dead at around 10:50 a.m.
"As an organization handling weapons, (the accident) should have never happened," GSDF Chief of Staff Gen. Yasunori Morishita told a news conference. "We take it seriously."
The GSDF has set up a committee to investigate the accident, while suspending all live-fire exercises nationwide until safety checks are completed.
About 20 personnel began the drill, which involved throwing grenades at targets, at about 8:30 a.m. at the Kitafuji training ground, according to the GSDF.
Yamamiya was an instructor in the drill.
A grenade a participant had thrown near the target exploded as intended, but shrapnel from the grenade hit the sergeant at around 8:45 a.m.
The GSDF is investigating the circumstances of the accident.
Participants in such a drill are required to take cover behind a shield after a grenade is thrown.