Police investigating an apparently unprovoked stabbing on a Tokyo street have arrested a man in his 30s.

The suspect, an unemployed man from Tokyo's Shinagawa Ward, reportedly told them he simply wanted to kill someone.

He is suspected of attacking a man in his 60s with a knife on a street near JR Gotanda Station.

Police say the suspect, whose name was not disclosed, stabbed the man in the back as he stood waiting for a taxi at around 11:10 a.m. on Tuesday.

The victim, although slightly wounded and bleeding, disarmed the suspect, who was arrested as he walked away.

The two men were unacquainted, media reports said.