A man carrying a knife in each hand and screaming “I will kill you!” has attacked a group of schoolgirls near a school bus parked at a bus stop just outside Tokyo, killing two people and injuring at least 17 before killing himself.

Most of the victims were students at a Catholic school who were lined up at the bus stop near Noborito Park in the city of Kawasaki when a man in his fifties began slashing them with knives.

City officials, quoting police, said the suspect was captured but died from a self-inflicted slash in his neck.

Witnesses described a hellish scene: children and adults falling to the ground, some with their shirts soaked with blood, dozens of children running and screaming for help, and school bags and books scattered on the ground.

“I heard a scream so I stopped and turned around to see what happened. It was not a normal tone of voice,” said Yasuko Atsukata.

She said she saw one person collapse, and then another.

“The colour of their white shirts turned red after they collapsed, then I understood they got stabbed.”

In a nearby car park, a frightened-looking boy was in shock with scratches on his face, hands and legs, apparently from falling to the ground as he ran for his life.

Police identified the attacker as Ryuichi Iwasaki, a 51-year-old resident of Kawasaki, and said they were still checking his occupation.

His identity and motive were not immediately known.

Japan Stabbing Attack
Police officers investigate the scene (Jae C Hong/AP)

Iwasaki reportedly lived with his elderly uncle and aunt and was known as a troublemaker.

A neighbour said Iwasaki repeatedly rang her doorbell early one morning about a year ago and shouted at her husband that he had been hit by a tree branch sticking out from their garden, the Sankei newspaper reported.

Kawasaki city official Masami Arai said most of the injured were students at Caritas Gakuen, a Catholic school founded by Soeurs de la Charite de Quebec, an organisation of Catholic nuns in Quebec City in Canada.

Arai said three of the injuries were serious.

Kanagawa prefectural police confirmed 17 people were injured and three others had died, including the attacker.

Police identified the two other fatalities as 11-year-old Hanako Kuribayashi and Satoshi Oyama, a 39-year-old government employee who was taking his child to the bus stop.

Hospital officials said both had been slashed in the neck and the head.

Caritas chairman Tetsuro Saito said at a news conference that he was “struggling to fight back my anger”.

Japan Stabbing Attack
Students leave their school with parents following the attack (Shinji Kita/Kyodo News via AP)

“My heart is broken with pain when I think of the innocent children and their parents who send their children to our school with love who were victimised by this savage act,” he said.

School officials said they will step up security measures at the school, including adding more security guards.

But the incident raises questions about how schools can ensure the safety of children while commuting.

Japanese children often walk to local schools in groups.

Witnesses said that as the attack unfolded, the bus driver shouted at the attacker, and as he was running away he cut his own neck, collapsing in a pool of blood as police seized him.

Japanese media including public broadcaster NHK said he was a 51-year-old resident of the city and that police found two more knives in his bag in addition to the two he was holding.

School officials at a news conference
School officials at a news conference (Jae C Hong/AP)

Television footage showed emergency workers giving first aid to people inside an orange tent set up on the street, and police and other officials carrying the injured to ambulances.

Prime Minister Shinzo Abe said he was outraged by the attack.

“Many small children were victimised, and I feel strong resentment,” Mr Abe said as he was hosting US President Donald Trump on a four-day state visit, which ended on Tuesday.

“I will take all possible measures to protect the safety of children.”

Although Japan has one of the lowest crime rates in the world, it has had a series of high-profile killings, including in 2016 when a former employee at a home for the disabled allegedly killed 19 people and injured more than 20 others.

Also in 2016, a man stabbed four people at a library in north-eastern Japan, allegedly for mishandling his questions.

No-one was killed.

In 2008, seven people were killed by a man who slammed a truck into a crowd of people in central Tokyo’s Akihabara electronics district and then stabbed passers-by.