Two Japanese soldiers were killed and another wounded when a new recruit opened fire at a military training range in central Japan, officials said.
An 18-year-old trainee was taken into custody at the scene and arrested on suspicion of attempted murder, police said.
They allege the male shooter fired eight times at the instructors during a shooting practice in Gifu on Wednesday.
Officials said a 25-year-old man was among the dead.
Details about the other victims, who are in their 20s and 50s, are not yet known. But they were all instructors at the facility.
Japan’s Ground Self-Defense Force said no civilians were involved.
They said the shooting took place during live fire training for new members and potential candidates. The accused had joined the force in April.
After Wednesday’s attack, live-fire and explosives training exercises were suspended nationwide, the head of Japan’s Self-Defense Forces said.
Incidents of gun violence are still extremely rare in Japan, but there have been some notable incidents in the past year.
Former Prime Minister Shinzo Abe was shot dead by a protester at a political rally last July. Abe was Japan’s longest-serving prime minister and his death deeply shocked the country.
Japan was rocked again in April when Prime Minister Fumio Kishida was safe after a smoke bomb was thrown at his election campaign.
And in May, a Japanese man killed four people, including two police officers, in an hours-long stabbing and shooting rampage in the Nagano area.
On Wednesday, pictures in Japanese media showed police and emergency vehicles blocking roads around the training facility in the city of Gifu.
Japan’s Chief Cabinet Secretary Matsuno Hirokazu said he was aware of the shooting, and said the incident was still under investigation.
Japan has strict gun ownership laws, and only allows civilians to own hunting rifles and airguns. In order to buy a gun in Japan, people have to pass a strict background check and a mental health test.
