Metal detectors should be installed in schools to discourage knife-carrying among youths, London's mayor has said.
Ken Livingstone has criticised violence on television and on film
Ken Livingstone said some young people did not fully grasp the potential consequences of going around armed.
"They carry a knife not realising they could one day get involved in a fight and be injured," he said.
The mayor's remarks follow the deaths of at least five teenagers in London in the past three months from shootings and stabbings.
He has blamed films such as Quentin Tarantino's Kill Bill, the TV series 24 and some rap music for glorifying violence and fuelling the gun and knife culture.
"Were it my area of responsibility I would have a metal detector in every school," he told a City Hall press conference.
The mayor recognised it would be expensive and stressed he had no authority to introduce such a policy.
He called for greater censorship saying: "We should be saying no. We need to mitigate violence.
"I think it is very important that we reinforce a moral code."
A Department for Education and Skills spokesman said the use of metal detectors in schools was down to individual head teachers.
"However, while some schools might find using detectors appropriate, a blanket use of airport style scanners in every one of the 24,000 schools in England may not be the most effective approach," he said.
Carole Whitty, of the National Association of Head Teachers, said metal detectors in schools may not foster the development of values such as mutual trust and respect.
"Ken Livingstone is right to say that young people who carry knives do not realise the consequences of doing so," she told the BBC News website.
"They will not learn that by being caught by a metal detector.
"It is urgent that we work together to empower our children and young people to take a lead in ensuring that there is a clear moral code built on mutual respect, rights and responsibilities."