A woman was arrested after allegedly slashing and stabbing other passengers with a blade on a train of Tokyo's Yamanote loop line on Wednesday night, police said.
The woman, believed to be in her 20s, attacked passengers as the train was running between JR Okachimachi and Akihabara stations, the police said, adding that the suspect was apparently unknown to those assaulted.
Four men sustained injuries to their sides, backs and arms in the attack, the police said.
Police arrested her on suspicion of attempted murder and seized the blade, they said.
Responding to the attack, people pressed emergency buttons installed in the train and on the platform of Akihabara Station once the train arrived, and a station staffer called the police at around 10:55 p.m.
The incident led JR East to temporarily suspend part of the loop train service in the capital.
The suspect was subdued by passengers on the train and handed over to police, the police added.
