The Saitama prefectural board of education said Wednesday cell phones will be banned from public elementary and junior high schools.
The board announced the decision in the prefectural assembly and urged high schools to restrict use of mobile phones as well.
The board said that 95 percent of public junior high schools already ban students from bringing their cell phones to school but only half stipulate this in written rules.
The board said it adopted the ban to help children become aware of the dangers of bullying and other crimes committed via mobile phones.
In July, the education ministry urged all prefectural boards of education to hammer out rules on using cell phones at school.
The Osaka prefectural board of education recently introduced a ban on the use of cell phones at all public elementary and junior high schools in the prefecture.
Students often set up Web sites that can be accessed by mobile phones. These sites are sometimes used to create a forum for exchanging messages to harass other students.