A man suspected of groping a teenage girl caused havoc for Tokyo's trains after he jumped off a platform and fled along the railway tracks.
Tokyo's trains can be extremely busy during rush hour
Services on all five lines in the vicinity were stopped when staff realised a man was on the tracks, in the path of the oncoming trains.
Tens of thousands of rush hour commuters were delayed as a result.
Rail staff ran after the man on the tracks of the Saikyo Line, but have so far been unable to catch him.
Police had apprehended the suspect at JR Akabane station in Tokyo on Wednesday morning, after a 15-year-old high school student accused him of groping her.
While she was reporting the incident to station staff, the man jumped from the platform and ran along the rail tracks leading into the station, according to Japanese newspaper the Asahi Shimbun.
An estimated 80,000 commuters suffered delays as 37 trains on the Keihin-Tohoku Line, Saikyo Line, Utsunomiya Line, Takasaki Line, and Shonan-Shinjuku Line were affected.
Sexual harassment has been a significant problem on Japan's trains for years, with rail companies introducing women-only carriages as a result.