The suspect in a Halloween stabbing and fire attack on a Tokyo train expressed admiration for infamous comic villain the Joker, Japanese media reported, with authorities describing the incident as "atrocious and brutal" on Monday.

Police said they arrested a 24-year-old man for attempted murder over the Sunday evening attack which caused 18 people to be hospitalised, as videos aired of officers surrounding a man in a purple suit with a bright green shirt and tie, reminiscent of the Batman villain.

The incident sparked panic and chaos in a country where violent crime is rare, and TV footage showed terrified passengers running through the train as smoke filled the carriage.

"With a knife he was carrying, the man stabbed the right side of the chest of a male passenger in his 70s sitting in the train, but couldn't achieve his aim (of murder)," a Tokyo police spokesman told AFP.

"He told police he wanted to receive a death sentence by killing someone," the spokesman added.

The elderly man is in a critical condition after being stabbed, according to media reports.

Top government spokesman Hirokazu Matsuno described the incident as "atrocious and brutal" on Monday.

The attacker told police he admired the Joker, Kyodo News and the Sankei Shimbun daily reported.

He said he had "failed in jobs and friendship and wanted to die but couldn't die himself", the Sankei said.

Batman's arch-nemesis is regarded as one of the most notorious psychopaths in comic book history. The 2019 film "Joker" sparked criticism of its portrayal of the murderous villain as an outcast hero, with US authorities warning of copycat attacks after the movie's release.

Before Sunday's attack, the suspect walked around Tokyo's Shibuya district, a busy area full of young people in Halloween costumes, the Sankei reported.

He said he had worn the outfit especially for the attack, it added.

"First I thought it was something like a Halloween event. But I rushed away as a man carrying a long knife came in. I was very fortunate not to be injured," a man who was on the train told NHK.

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

"He held a knife and started spreading liquid," she said. "He was committing this act without showing any emotion, just mechanically. I think that brought fear to everyone."

The assailant reportedly said he had used a stabbing attack on a commuter train in Tokyo in August as a reference. In that attack, nine people were wounded, one of them seriously.

In a separate attack, also in August, two people suffered acid burns at a Tokyo subway station.

Japan's worst attack on members of the public in recent decades was in 1995, when members of the Aum Shinrikyo cult released sarin gas on the Tokyo subway, killing 13 people.