A man carrying a knife in each hand and screaming 'I will kill you!' attacked a group of schoolgirls and adults near a bus stop just outside Tokyo on Tuesday, killing two and injuring 16 before killing himself, officials said.

Most of the victims were schoolgirls who were lined up at a bus stop near Noborito Park in the city of Kawasaki when a man in his 50s began slashing them with knives. City officials, quoting police, said that the suspect was captured but died from a self-inflicted cut to the neck.

Police wouldn't immediately confirm specifics about the attacker.

Masami Arai, an official at the Kawasaki city office, said 16 people, most of them schoolgirls at a local Catholic school, were injured and three others, including the attacker, were believed killed. Arai said three of the injuries were serious and 13 others were not life-threatening.

Kanagawa prefectural police only confirmed the death of sixth-grade schoolgirl Hanako Kuribayashi, 11, from Tokyo. Hospital officials at a televised news conference confirmed the 11-year-old's death as well as that of a man in his 30s, saying both of them had been slashed in the head, chest and face.

Separately, doctors at St. Marianna University School of Medicine, said a man in his 50s died at the hospital after being brought in from the crime scene with neck injuries. City officials and the media said the man is the suspect.

Most of the victims attended Caritas Gakuen, a well-known private school founded by Soeurs de la Charite de Quebec, an organisation of Catholic nuns in Quebec City in Canada.

All but two adult victims are in elementary school, according to city and hospital officials, and their ages are believed to be from 6 to 12. The school runs from elementary through high school.

A witness told the Mainichi newspaper that he heard children shrieking after walking past a bus. He said that when he turned around, he saw a man wielding a knife in each hand, screaming 'I will kill you!' and several children were on the ground.

NHK, citing police, said that a bus driver told officials that a man holding a knife in each hand walked toward the bus and started slashing children, then the attacker ran away when the driver yelled at him, 'What are you doing?' then cut himself. NHK also interviewed a witness who said he saw the suspect trying to force his way onto a bus. A third witness said he saw a school boy with scratches on his face, hands and legs, sitting on the ground of a parking lot, looking frightened.

The attacker's identity and motive weren't immediately known.

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.

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 and injured more than 20 others.

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.

Also in 2016, a man stabbed four people at a library in northeastern Japan, allegedly over their mishandling of his questions. No one was killed.