British officials say they're pressuring Facebook to make a "panic button" available on its web pages following the death of a teenager at the hands of a man she met on the popular social networking site.

British child protection authorities have been lobbying Facebook and other social networking sites to install a one-click button which can allow children to get immediate police help if they suspect they're at risk.

Calls for Facebook to install the button intensified following the kidnap, rape and murder of 17-year-old Ashleigh Hall.

Her killer, Peter Chapman, used a bogus Facebook identity to befriend her online.

Harriet Harman, the deputy leader of Britain's governing Labour Party, said that ministers were lobbying Facebook to adopt the button.