There have been a spate of cases of paedophiles using chatrooms

"Safer surfing" will be presented by Metropolitan Police officers to 10 and 11-year-olds in the classroom.

The new programme comes two weeks after a man described as the UK's most prolific paedophile "groomer" was sentenced to five years in prison for the attempted abduction of a teenager.

Douglas Lindsell, 54, had bombarded girls he had met on the internet with messages and phone calls.

Scotland Yard says five million children aged nine to 16 regularly use some of the 100,000 internet chatrooms every year in the UK with paedophiles often posing as teenagers to win the confidence of their victims.

The message the police say they want to get across is to "have fun and be safe".

They urge children not to keep secrets, not to open attachments and remain in public chatrooms.

'Vital learning tool'

Deputy Assistant Commissioner Bill Griffiths, the Met's Director of Serious Crime, said: "The web is a valuable and exciting tool, but we must not underestimate the power it has to reach our children - and be misused."

John Carr, internet adviser for the charity NCH Action for Children, told BBC London the scheme is a vital learning tool for children.

He said: "It leads them to various conclusions about the possible consequences. I've seen it, it's great, it really works.

"When the kids realise what's going on their jaws drop, the penny drops and that's the really important learning point for them."