TEMPO.CO, Jakarta - A 24-year-old man dressed in Batman's Joker costume attacked passengers on a Tokyo train line on Sunday evening, injuring 17 people as many party-goers headed into the city centre for Halloween gatherings, media reported.

Police arrested the suspected attacker on the spot, media reported. A man believed to be in his 60s was unconscious and in critical condition after being stabbed, while witnesses also said the attacker had spread fluid around the train and started a fire, according to media.

Smoke is seen in a Tokyo train line carriage following a knife attack incident in Tokyo, Japan, Sunday evening, October 31, 2021. The assailant is said to have spread liquid around the train and ignited a fire inside the carriage. TWITTER / @SIZ33/via REUTERS

One video uploaded on Twitter showed a steady stream of people running away from a train car where, seconds later, a blaze lit up. Another video showed passengers rushing to squeeze out of the train's windows and onto the platform where the train had made an emergency stop.

People flee through the windows of a Tokyo train line following a knife attack in Tokyo, Japan, Sunday, October 31, 2021. A man in a Joker costume attacked passengers on a Tokyo train line on Sunday night. TWITTER / @SIZ33/via REUTERS

"I thought it was a Halloween stunt," one witness told the Yomiuri newspaper, recalling the moment he saw other passengers running in a panic towards his train car. "Then, I saw a man walking this way, slowly waving a long knife." There was blood on the knife, he said.

Another video on Twitter showed a bespectacled man dressed in a purple suit and bright green shirt, as worn by the Joker, seated in an empty train puffing on a cigarette, his legs crossed and looking calm. He can be seen through the window being surrounded by law enforcement in a subsequent clip.

Local media reported later that the suspect told authorities he "wanted to kill people so he could be sentenced to death".

The attack occurred on the Keio express line bound for Shinjuku, the world's busiest rail station, at around 8 p.m. (1100 GMT), media said.

Partial service on the Keio line remained suspended late on Sunday, when Japanese voters went to the polls in a lower house election.

Read: Japan Logs New High Number of Severe Covid-19 Patients

REUTERS