"Shocking levels" of sexual violence are being carried out by children against other children as young as 11 across the country, according to a report by the Office of the Children's Commissioner for England.
Its report said Council chiefs said work by agencies on child protection needed to improve. The report is the result of a two-year inquiry by the Commissioner into child exploitation and found that bullying and sexist attitudes were widespread with rape seen as "normal" within gang culture.
Shocking and saddening
Anne Longfield, chief executive of children's charity 4Children, described the report as shocking and saddening.
"Our work shows us that the earlier you help children and families the better the chance they have from breaking out from a negative and often intergenerational cycle of poor relationships, parenting and often violence," she added.
The report says legislation is there to protect children but agencies from the police to social services need to become far better at spotting children at risk and providing them with the necessary protection.
In a foreword to the report, Deputy Children's Commissioner Sue Berelowitz said the findings showed the "appalling reality" of sexual violence committed by young people.
"We have found shocking and profoundly distressing evidence of sexual assault, including rape, being carried out by young people against other children and young people.
"While we have published chilling evidence of this violence in gang-associated contexts, we know too that it is more widespread than that. This is a deep malaise within society from which we must not shirk."
Prevalent in every type of neighbourhood
The inquiry found that 2,409 youngsters were known to be victims of child sexual exploitation by gangs and groups, while a further 16,500 were at risk.
It warned that the problem was prevalent in every area of England, and was not restricted just to low-income, inner-city neighbourhoods but "in every type of neighbourhood, rural, urban, deprived, not deprived".
The report condemned 94% of safeguarding children boards - which are run by local authorities, police, the NHS, the probation service and other groups - for failing to follow government guidance on tackling child exploitation, and set out recommendations for a new framework.