Japan Train Attack Suspect, Batman's 'Joker' Fan, "Planned For Months": Police

Tokyo stabbing and arson attack, which briefly sent fire flaring in a train carriage, was carried out on Sunday night.

A drifter who admired the Joker from Batman and dressed as him to carry out a Halloween attack on a Tokyo train "wanted to kill lots of people" and planned his moves over months, buying a knife to use in the internet, police and media said on Tuesday.

The stabbing and arson attack, which briefly sent fire flaring in a train carriage, was carried out on Sunday night as many party-goers headed into Tokyo for Halloween celebrations and sent passengers screaming down the aisles of train carriages and scrambling out of windows to escape.

One man in his 70s remains in a serious condition with stab wounds to his torso and 16 others were treated for minor injuries, mostly smoke inhalation, a police spokesman said.

Kyota Hattori, 24 and dressed in multi-coloured clothing as the Joker, was arrested on the spot and later told investigators "I wanted to kill lots of people, I wanted the death penalty," the police spokesman added.