Six hundred schoolchildren were given first-hand accounts of life in prison as part of a nationwide campaign to reduce knife crime. The North Oxfordshire Academy, in Banbury, was the first school in the county to take part in workshops aimed at persuading young people not to carry knives.

Former prisoner Ahmet Kashli, founder of New Destiny Trust, which runs the workshops, and Syd Syed, who is still serving a nine-year sentence for possession of a gun and cocaine, talked to 13 to 17-year-old pupils about how they had ended up in prison, and the consequences of carrying or using weapons.

The even was held on the day the Oxford Mail printed pictures of county teenagers brandishing knives and guns they had posted on the Internet.

A group of about 100 pupils was asked to stand up if they either knew someone who carried a knife or had carried one themselves — about half stood up. A further 11 said they would carry a knife for self-defence.

One pupil, named Jack, said he had been threatened with a knife and the person holding it was egged on by friends to use it.

The pupils were shown graphic photographs of knife wounds, including one of a girl who was stabbed in the head and later died.

Pupils were urged not to bow to peer pressure and told if they were feared an attack, they should run.

Afterwards, Usman Yasan, 16, said: "It was good for the younger kids as well. I'm against carrying knives."

Saffron Ruff, 17, said: "I thought it was quite informative. It was nice to get all the information from someone who has gone through it, rather than someone who didn't actually know what they were talking about.

"I wouldn't carry a knife. I don't think violence is the way forward."

But she said that she knew people who did carry knives. Nicola Maycock, 16, said: "Before, I didn't think it was a big deal, but it's serious danger."

Mr Syed said: "When we do these, I look at it if we can stop one in 10, if we can make them think before they take action, then we have done a tremendous job."