London ? England’s commissioner for children and a civil liberties group joined in a campaign Tuesday to ban high-frequency devices intended to drive away kids who congregate outside shops and in other areas.

The so-called “Mosquito” device emits high-frequency noise that is audible – and annoying – to young ears, but generally not heard by people over 20.

The campaigners claim that about 3,500 of the electronic kid repellents, made by a Welsh company, are in use.

Youth crime is a major concern in Britain; according to the crime prevention charity Nacro, young people are responsible for two-fifths of incidents of theft, burglary, robbery and violence.