Japan's Education Ministry has ordered superintendents nationwide to crack down on schoolyard bullying that has led to a string of students killing themselves and triggered concern that suicide could become a tragic adolescent fad.

The order, issued in a first-ever meeting in Tokyo of education chiefs from across Japan, came as police reported the sixth victim in three weeks in a rash of student suicides.Many of the victims have suffered repeated schoolyard bullying, underscoring strain in Japan's schools over a longstanding but worsening trend of violence.

A tearful education ministry official appealed at the meeting to students not to take their lives to escape bullying and other problems. "Please don't make your parents sad," he said.

In the latest suicide, a 13-year-old junior high school student jumped in front of a racing train Thursday night in Saitama Prefecture just north of Tokyo. He left no suicide note.

Earlier the same day, a 14-year-old student in a nearby town swung a rope over a beam in his school's tennis club and hanged himself.

In a note he said his death was an experiment to find out if people went to heaven or hell. Police said it could have been prompted by other student suicides.

They also revealed Friday that the trend had claimed its first female victim. A schoolgirl jumped to her death from an apartment block in Osaka western Japan early this week.

"We are very concerned about the series of suicides and other possible suicides in the future," Education minister Kaoru Yoshino said Friday. His ministry has come under fire from critics for putting too much pressure on students.

Earlier this week, Prime Minister Tomiichi Murayama called an emergency Cabinet meeting to discuss the bullying and urged teachers, students and parents to work together to halt the problem.

The rash of deaths began with the Nov. 27 suicide of Kiyoteru Okochi, who hanged himself in his backyard. The 13-year-old left a note saying bullies repeatedly forced him to steal money.