Bulletproof white-boards installed in US schools as protection measure
Bulletproof white-boards are being introduced in some US schools - in what is being seen as adding a last-resort layer of safety for teachers and students.
The boards use a material apparently stronger than police-issue bulletproof vests - and can be used as a shield in an emergency.
Among the places where they are being installed is the Rocori School District in Minnesota, which has acquired nearly 200 of them.
The board's manufacturer has been working on armour protection devices for military personnel for years.
It turned its attention to school security after the Connecticut school shootings last December that killed 20 children and six teachers.
