Video report by Social Affairs Correspondent Emily Morgan
A leading trauma surgeon in London has told ITV News he is regularly treating children in school uniform for knife wounds.
Dr Martin Griffiths, a lead surgeon at Barts Health NHS Trust, say an increasing number of children are arriving with multiple injuries.
His comments come during a spate of violent attacks in London that have left more than 50 people dead so far this year.
"Thirteen and fourteen-year-olds are pretty routine now but I've had as young as nine years of age with stab wounds and gunshot wounds", he said.
Speaking about the spate of recent attacks, Dr Griffiths said: "The injuries that they're sustaining are changing, we're seeing more stab wounds per victim.
"We're also seeing more severe injuries requiring much more complex surgery."
He also said the age of the victims - and their apparent assailants - was dropping.
The trauma specialist, who works with victims well after they leave the hospital, said there has to be a massive culture change in order to improve the situation.
"What troubles me now is not the number and the severity of the injuries, the youth of the victims but the acceptance in the voice of the parents when I tell them their boy has been stabbed or shot," he said.
"They expect it to happen, they've been waiting for it to happen - that's what horrifies me."
Ten years ago, teenager Jimmy Mizen was killed by 19-year-old Jake Fahri, who threw a glass dish at him after a disagreement in a bakery in Lee Green. Fahri was sentenced to life imprisonment for murder.
Jimmy's father told ITV News that everyone in society must help to reduce crime.
Barry Mizen said: "It has to be community led because strong communities are safe communities.
"We have lost something there and seem to wait on someone else to do these things for us - I understand the passion behind marches and telling some to do something but what are you prepared to do?"
His comments come as London struggles to grapple with a spate of murders, with more than 50 cases of homicide being investigated by Scotland Yard since the start of the year.
In February, London's murder rate was higher than New York's for the first time ever.