A secondary school plans to ban its pupils from bringing in mobile phones as a way of stopping bullying via text.
The school has adopted a strong anti-bullying policy
Students at Duffryn High School, in Newport, will be banned from bringing their phones to school after Easter.
It follows problems where some children received intimidating text messages which were sent anonymously.
Children's Commissioner Peter Clarke said schools needed to ensure such action did not merely move the problem to out of school hours.
The ban is being introduced as part of the school's anti bullying initiative, where sixth form students act as "pals" to the younger children.
Sue Gruffydd, assistant head teacher, said that the problem of text bullying was hard to tackle because new technology meant that the bully could not easily be traced.
Sue Gruffydd describes bullying via text "cowardly"
She said victims were often made to feel more intimidated because they were not able to find out who was sending the text messages.
Ms Gruffyd said the problem of bullying via emails and texts was particularly hard to deal with.
"If someone is being physically bullied, we can see it and do something about it," she said.
"But with the text messages and emails, it is so hard to prove who has done it."
She said the school became aware of the problem of text and email bullying through the Peer Active Listening (Pal) scheme where younger pupils confide in sixth formers.
"One of the things to come out of the Pal scheme is that bullying via text and email is becoming more prevalent," she said.
"It is so difficult to be able to prove who has sent the text message because we are not policemen.
"It is a real cowardly way of bullying," she said.
Ms Gruffydd added that the ban on mobile phones was also to encourage better social skills among the students and not solely to try to stop bullying.
Children's commissioner Peter Clarke said: "One thing which is distinctive about this school is that the young people came and talked to the teachers, and I think that is a great credit to them.
"There are a couple of issues that need to be borne in mind if a school is thinking of banning phones altogether.
"The first is it may just shift the problem to out of school hours and it may be that some children have less support out of hours than they do when they are at school.
"The second is that some people use their phones to ring people like Childline when they are being bullied during the school lunch hour.
"The last thing is, as parents know, mobile phones can help if a child had decided to go around to a friend's on the way home from school."
But he added: "I don't think these problems need be insurmountable."