The suspect in an attack on Prime Minister Fumio Kishida last month will undergo a psychiatric examination for about three months, sources close to the matter said Monday.
A summary court in Wakayama, western Japan, has granted a request from prosecutors to keep Ryuji Kimura detained for the examination, expected to begin soon, to fully assess his mental state at the time of the attack.
The 24-year-old from Hyogo Prefecture has been served a fresh arrest warrant by police on suspicion of violating the firearms control law by manufacturing explosives.
Investigators said Kimura has remained silent since his arrest. Court documents show he may have harbored a grudge after he was unable to file his candidacy for a House of Councillors election held last year.
The suspect was arrested at the scene on April 15 on suspicion of obstructing business after throwing an explosive device at Kishida, who was about to make a stump speech at a local fishing port in the city of Wakayama.
While the prime minister was unhurt, two people, including a police officer, sustained minor injuries.
The incident comes less than a year after former Prime Minister Shinzo Abe was fatally shot when giving a stump speech in Nara Prefecture.