The government launches a 3 million pound national advertising campaign on Thursday to warn young people about the effects of knife crime amid growing fears that the issue is getting out of control.

Actor Robert Knox became the latest teenage stabbing victim on Saturday when he was knifed to death outside a pub in Sidcup, Kent, prompting renewed calls for something to be done to stop young people carrying knives.

The "hard-hitting" adverts, which will be run on radio, Web sites and mobile phones, will warn youngsters about the harsh physical and emotional consequences of knife crime, the government said.

The 3-million-pound campaign, to be run over the next three years, was developed and written by young people who have themselves been affected by knife crime.

A series of ads aimed at mothers, encouraging them to talk about the issue with their children, will run simultaneously.

"I am in no doubt about the importance of tackling knife crime and this is even starker following recent tragic events," said Home Office Minister Vernon Coaker.

"We know that many young people carry a knife because they are fearful and these adverts tell powerful stories about the dangers of going down that path.

"People have got to get the message that if they carry a knife, there's more chance of it being used against them."

The adverts are the latest tactic to trying to address the growing political issue of knife crime.

Home Secretary Jacqui Smith has already promised extra money to tackle gangs and youth violence, with an emphasis on extra police use of stop and search powers.

That echoes a crackdown launched earlier this month by police in London. Teenagers in areas blighted by weapons, or groups suspected of carrying knives, face being searched without officers needing to have reasonable suspicion.

Senior officers said it would be "in your face" policing.

However, critics have said that the issue requires more than tough police measures, and Metropolitan Police Commissioner Ian Blair himself has said parents needed to confront their children about carrying knives.

"Every mother, father and carer has the responsibility to ensure this happens," said Angela Lawrence, from Mothers Against Violence. "The senseless killing of our children by knives and guns has to stop."