A man accused of throwing a pipe bomb at Japanese Prime Minister Fumio Kishida in April has been charged with attempted murder, a court spokeswoman said Wednesday.

Ryuji Kimura, 24, is suspected of tossing the explosive device towards Kishida during a campaign event in western Japan.

Kishida was unharmed after the attack, while Kimura was arrested at the scene.

The incident came less than a year after former leader Shinzo Abe was assassinated on the campaign trail.

A Wakayama district court spokeswoman told AFP Kimura "was indicted" on Wednesday.

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

Kimura has remained silent since his arrest, according to public broadcaster NHK.

Kimura reportedly underwent psychiatric evaluation for about three months before being charged.

Kimura had previously filed a lawsuit against the government, complaining about the country's minimum age for running in elections.