New figures obtained by the NSPCC show more than 8,000 under 18s were accused of sexual offences against other children in the last two years.
In a freedom of information request submitted by the children's welfare charity, it found Thames Valley Police alone had recorded 110 cases of under 18s abusing youngsters in the past two years.
Nationally, the youngest perpetrator was aged seven and the youngest victim just two-years-old.
The figures showed abusers were mostly male but there was also a small proportion of female abusers as well, while the victims were also of both sexes.
Crimes included serious sexual assaults, rape, and obscene publication offences.
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