A teenage trainee shot three fellow soldiers at a Japanese army base on Wednesday, killing two of them, officials said.
Police said the 18-year-old had been arrested on suspicion of attempted murder in Gifu prefecture, central Japan.
The suspect fired a rifle at other soldiers during a shooting exercise at the Hino Kihon firing range, police said, saying a 25-year-old soldier was among those hit.
The Ground Self Defence Force, Japan’s army, confirmed two of those shot were pronounced dead at a hospital.
A number of other people were believed to be participating in the training when the shooting occurred.
Japan has been known for its safety with strict gun control laws, but high-profile violence has occurred in recent years, including shootings and random knifings on subways and arson attacks, and there is growing concern about homemade guns and explosives.
Prime Minister Fumio Kishida was almost hit by a pipe bomb thrown by a suspect at an election campaign venue in April.
Former Prime Minister Shinzo Abe was assassinated in July 2022 by an attacker using a handmade gun.
Last month, a man was arrested after he allegedly shot two police officers to death after killing two women with a knife in Nagano.
