A stunned Japan was searching for answers on Wednesday after an 11-year-old schoolgirl killed a classmate by slashing her throat, the latest in a string of violent crimes by children.

Japan, which had long prided itself on being relatively crime-free, has in recent years been confronted by an increasing number of gruesome youth crimes that have prompted it to lower the age of criminal responsibility.

Teachers and friends said the 11-year-old had shown no sign of trouble and described her as just like any other girl, adding to the shock.

"It is difficult to imagine how such a very serious incident could come from such an ordinary girl from an ordinary family," said the head of a child welfare center that took custody of the girl.

Twelve-year-old Satomi Mitarai died from loss of blood after she was attacked by the classmate, said to be her friend, with a knife during the lunch break on Tuesday at their primary school in Sasebo, 980 km (610 miles) west of Tokyo.

There was no obvious motive for the attack, but Japanese media said the 11-year-old told police that she had been upset at Satomi for posting a message about her on a Web site and that she had intended to kill Satomi over it.

The Yomiuri Shimbun daily reflected the general bewilderment, asking in an editorial, "What sort of connection did these two have? What set it off? Nothing is known."

Police said the 11-year-old had called Satomi to a study room where she attacked her and then returned to the classroom with her clothes bloodstained.

Child welfare workers said the girl repeatedly apologized for the crime, covering her face with her hands as she wept, according to media reports.

The victim's widowed father, who lived alone with her and her older brother, said he was in shock.

"That my daughter could no longer be with me is unbelievable. But the unbelievable has happened," Kyoji Mitarai, the local bureau chief of the Mainichi Shimbun newspaper, told reporters.

"She was like air to me," he said.

Rising crime, tighter laws

The killing appeared especially shocking because of the age of the children involved and the fact that both were girls.

Officials said the girl in Tuesday's incident would appear before a family court, which could send her to a special reformatory for children.

Children under 14 cannot be prosecuted.

In 1997, a 14-year-old schoolboy horrified the nation by murdering two children and leaving the severed head of one of them outside the gates of a school in Kobe, western Japan.

That crime prompted calls for harsher penalties against juveniles, and a law was enacted in 2001 lowering the age of criminal responsibility from 16 to 14.

The number of serious crimes by juveniles has continued to rise, however, with the ages of offenders falling.

Last year, a 12-year-old boy in the city of Nagasaki, which is near Sasebo, confessed to abducting and murdering a four-year-old by pushing him off the roof of a garage.

According to police figures, the number of minors aged 14 to 19 who committed serious crimes such as murder and robbery rose 11.4 percent to 2,212 in 2003, while the number of offenders under 14 rose 47.2 percent to 212, topping the 200 level for the first time in 16 years.

There have been eight cases where primary school children have committed or attempted murder in the last 15 years.

Police have drawn up new guidelines on fighting juvenile crime, but editorials on Wednesday said more fundamental measures may be needed.

"We must make children understand even more the basic importance of life," the Yomiuri said.

(China Daily via agencies, June 3, 2004)