Metal detector arches have been installed at schools

Pupils at Slough Grammar School, Berkshire, took part in the first day of Operation Blunt - a campaign to cut knife crime across the Thames Valley.

As well as searches, metal detector arches have been erected at school gates and shopping centres.

It follows research by the Damilola Taylor Trust showing 80% of knife crime is committed by 12 to 20-year-olds.

The trust was established by the parents of the late Damilola, who died aged 10 after being cut with a broken bottle in Peckham, south London, in 2000.

Dangerous culture

Heidi Watson, chief executive of the trust, said: "If you carry a knife it could get used against you.

"This is a very important campaign and we are pleased to be working with Thames Valley Police - we want to build a culture of safety and not of self protection."

Metal detector arches will also be put up in bus and train stations, a decision made following the national knife amnesty when 287 knives where handed in in Oxfordshire, and nearly 400 in Berkshire.

Acting Ch Supt Paul Tinton said: "We will use the search arches at knife crime hotspots to catch and prosecute people who are carrying knives illegally."

The head of Slough Grammar School said young people carrying knives is an issue that needed to be addressed.

Margaret Lenton said she wanted to let students and the public know "this culture is dangerous and will not be tolerated" in the school.