More than 150,000 children will be urged to secretly text details of classmates with knives in a groundbreaking new scheme.
Youngsters in 160 secondary schools and colleges in some of Britain's worst knife crime areas will take part in the project organised by the charity Crimestoppers. If successful it will go nationwide next year.
The launch is a victory for the Mirror's Stop Knives, Save Lives campaign - which has urged the use of a text messaging alert system. Hannah Daws from Crimestoppers said: "Because of the popularity of texting among youngsters we decided to use it.
"All we ask for is five pieces of information - the suspect's name, nickname, school, class year, and address."
Messages will be routed through special software to ensure they remain anonymous when passed to the police.
Police say a pilot scheme in three schools in Tower Hamlets, East London, has already given them vital information.
Hannah added: "From September we are going live in all the schools across fifteen London boroughs with the worst rates of knife crime. If that's also successful we'll roll out the scheme across Britain."
The idea was applauded by Sally Knox, whose actor son Rob, 18, was knifed to death outside a London bar in May.
She said: "Anything that enables children to get in touch with the police anonymously is a fantastic idea. Using texts makes it even better."