Kishida was unharmed in the attack with a homemade device at a campaign event where assailant Ryuji Kimura, 25, was arrested at the scene.

The incident in western Japan came less than a year after former prime minister Shinzo Abe was assassinated in July 2022 on the campaign trail.

Wakayama district court sentenced Kimura to 10 years in prison for attempted murder, media outlets including Jiji Press and public broadcaster NHK said.

The judge told the court Kimura had “carried out the act at the venue of an election speech, which is the foundation of democracy”, Japan’s Asahi Shimbun daily reported.

Prosecutors had sought a 15-year sentence while Kimura’s defence team had argued for three years because he denied intending to kill Kishida, Jiji reported.

A court spokesman could not immediately confirm the reports.

Suspected gunpowder, as well as pipe-like objects and tools were found at Kimura’s home during a police search after the attack.

At hearings during the trial, Kimura’s lawyers said his “purpose was to gain (public) attention” so his charge should be “inflicting injury” but not attempted murder, NHK said.

However, prosecutors reportedly called the incident a “malicious terror act” and said the attacker knew his explosive was lethal.

Previous reports said Kimura once filed a lawsuit challenging the minimum age for political candidates and the requirement that they have at least three million yen (US$19,700) to run for national office.

Under Japanese law, candidates for upper house elections must be 30 or older, while the minimum age to run for parliament’s lower house is 25.