Schools in London are not well enough supported when it comes to dealing with knife crime, a report from the schools watchdog, Ofsted, says.
Ofsted says that schools do not have the ability to address the complex societal problems that lie behind the rise in knife violence.
It says these issues need to be tackled by a range of partners, such as police, local authorities and policy-makers.
It also says exclusions are not the root cause of the surge in knife crime.
“Children who carry knives almost invariably have complex problems that begin long before they are excluded,” the watchdog says.
It also says serious violence on school grounds is “extremely rare”.
The Ofsted report, Safeguarding children and young people in education from knife crime – lessons from London, looks at how more than 100 schools, colleges, and pupil referral units (Prus) in London are protecting children from knife violence in school, as well as how they teach pupils to stay safe outside of school.
Chief inspector Amanda Spielman says: “Schools simply do not have the ability to counter the deep-seated societal problems behind the rise in knife crime.
“Some schools are valiantly trying to fund school-based early help services or other services that were once provided for free.
“But we cannot allow responsibility for this to be landed on schools in the absence of properly funded local services.”
Ms Spielman also says schools are worried about damaging their reputation if they talk about the issue.
“Many school and college leaders we spoke to were trying to educate children about the dangers of knife crime and the risks of grooming and exploitation by gangs.
“However, some are concerned that if they do this they will be seen as a ‘problem school’, and subsequently avoided by parents.
“Others were rightly prepared to be open with pupils and parents about the issues and how to deal with them.”