A man with a knife goes berserk and started a stabbing spree on a Tokyo commuter train on Sunday that wounded 10 people, one of whom was in serious condition.
Alert police officer manning the railway station immediately arrested the suspect who is in his 20s.
In the initial police investigation, the attack happened inside the Keio train near the Kokuryo station.
The local police are now interrogating the suspect for his motive in the sudden and senseless attack.
Sources said the stabbing incident at the Tokyo train is the second one to happen in two months.
Last August, the day before the Tokyo Olympics closing ceremony, a 36-year-old man stabbed 10 passengers on a commuter train in Tokyo in a random burst of violence.
Upon his arrest, the suspect said he committed the crime because he wants to attack women that looked happy.