TOKYO (AFP, YOMIURI SHIMBUN/ASIA NEWS NETWORK) - Japanese police on Wednesday (May 29) searched the home of the man behind a stabbing rampage in the town of Kawasaki a day earlier that killed two people, including a child.

The 51-year-old attacker, identified by police as Ryuichi Iwasaki, died after stabbing himself during the rampage, and his motives for the horrifying assault remain unclear.

On Wednesday morning, police searched his home, not far from the scene of the morning attack, seizing unspecified material, public broadcaster NHK reported.

Local media said Iwasaki was living with relatives in their 80s, but gave no further details.

Police had no comment on the investigation and declined to offer any further details about the attacker.

The rampage in the town south of Tokyo on Tuesday morning killed two people - 11-year-old schoolgirl Hanako Kuribayashi and a 39-year-old parent, identified as government official Satoshi Oyama, a Myanmar specialist.

Seventeen more people, mainly young children, were injured, according to authorities.

Iwasaki had crept silently up behind students of Caritas Gakuen (school) as they waited for their school bus and began slashing randomly at them with knives in both hands, before fatally stabbing himself in the neck.

By Wednesday morning, few details had emerged about the attacker and his motive for the assault, with neighbours telling local media that they knew little about the man.

According to local residents and acquaintances, Iwasaki was taken in by his relatives almost 40 years ago.

He attended local elementary and junior high schools, though a former classmate, now 51, said: "He was quiet and didn't stand out. I have no memory of him talking with friends."

However, other residents witnessed him get angry. A housewife in her 70s remembered being terrified when a young Iwasaki flew into a rage at her dog's barking. "It's noisy! How about I kill it for you?" she recalled him saying.

A woman in her 40s recalled an incident that occurred about a year ago. She said Iwasaki came to her house, pressing the intercom over and over. He yelled for about 30 minutes, complaining that a tree in her garden was sticking out into the road and had hit him in the eye.

The woman said she saw Iwasaki on Tuesday morning at about 7 a.m. in front of her house. He was wearing a black short-sleeved shirt and pants, and carrying a backpack, she said.

He said "good morning" to her, then ran off.

"It was the first time he'd spoken to me. Something felt strange, but I never imagined something like this would happen," she said.

NHK, citing local officials, said the suspect had been living with his uncle and aunt and that they and other relatives had consulted with Kawasaki city officials 14 times between November 2017 and January 2019 over their concerns about Iwasaki.

They told local officials that he had not held a job for a long time and had "hikikomori tendencies," using a term in Japanese for people who shut themselves off from the outside world, often for years.

But his relatives subsequently told the city to hold off contacting Iwasaki, officials said.

A man who identified himself as having taught Iwasaki in junior high school, when the suspect was around 14, told NHK he was "not the kind of child who stands out".

"He and his friends would shove each other playfully, but he didn't attack anyone violently," the teacher said.

In the wake of the attack, Japan's government said it would review measures to ensure the safety of children travelling to and from school.

Japan has one of the lowest rates of violent crime in the developed world, and it is common for even young children to take public transport alone to get to and from school.

"The whole government will work in unison to ensure the children's safety," government spokesman Yoshihide Suga told reporters after a ministerial meeting on the issue.

The attack shocked Japan, where violent crime is vanishingly rare, in part because of strict regulations on gun ownership.

On Wednesday morning, people were still arriving at the scene of the attack to lay flowers and other tributes to those killed.

The Caritas school will be closed for the rest of the week, and officials said on Tuesday that they would offer students mental health support after the attack.