A man stabbed at least 10 passengers on a commuter train in Tokyo, just five miles away from the Olympic stadium.
One passenger was seriously injured in the incident but the suspect was captured by police after fleeing the scene of the attacks, according to officials.
The Tokyo Fire Department says that nine of the victims were taken for treatment at nearby hospitals, while one person was able to walk away.
Authorities say that all of the victims remained conscious throughout the incident.
A witness at a nearby station where the train eventually stopped, said that panicked passengers had streamed out of carriages when it came to a stop.
NHK public television said a witness told them that passengers were smeared with blood, and an announcer had called for doctors on board and any passengers with towels to help.
The television station added that the suspect was caught after walking into a convenience store and telling people inside that he was tired of running away.
The store’s manager saw that the man, who is said to be in his 20s, was covered in blood and called the police.
The stabbing occurred near Seijogakuen station, according to railway operator Odakyu Electric Railway Co.
The Tokyo 2020 games are set to conclude on Sunday after 16 days of competition carried out at empty venues and stadiums because of the Covid pandemic.
Police has so far declined to comment on what exactly happened.
Although Japan generally has a low crime rate, it has seen a string of mass-casualty knife attacks in recent years.
In May 2019 a 51-year-old man went on a stabbing spree in the city of Kawasaki, in which he killed a 39-year-old man and a 12-year-old schoolgirl, and injured 15 other school children as they waited for a bus.
And in 2016, 19 residents at a care home for people with mental disabilities were stabbed to death by a former employee who confessed to the killing.
The Associated Press contributed to this report
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