A man who was dressed as Batman villain the Joker told police he wanted to be executed when they arrested him for attempted murder after he injured 17 people in a knife rampage onboard a Tokyo commuter train.

Witnesses described how the 24-year-old attacker stabbed 10 people and poured what is believed to have been oil around the carriage before lighting it on fire, causing panic among passengers.

It was also reported hydrochloric acid was thrown during the attack, which occurred on the Keio express line bound for Shinjuku, the world's busiest rail station.

The Tokyo Fire Department said in all 17 passengers were injured, including three seriously, in the Halloween attack.

Not all of them were stabbed and most of the injuries were not serious, officials added.

A man believed to be in his 60s was unconscious and in critical condition after being stabbed, according to media.

The attacker was arrested on the spot and is now being investigated on suspicion of attempted murder.

His motive was not immediately known but Kyodo reported that the suspect had told investigators he 'wanted to kill people and be given the death penalty'. He also told them he had spread lighter fluid in the train.

Nippon Television reported that the suspect told police he used an earlier train stabbing case as an example.

NHK said witnesses told police that the attacker was wearing a bright outfit - a green shirt, a blue suit and a purple coat which resembled that of the Joker from the Batman comics.

Tokyo police officials said the attack happened inside the Keio train near the Kokuryo station.

The attacker carried out the act without showing any emotion, a female passenger said.

Source: ANNnewsCH