North Yorkshire Police is appealing for information after the incident, which they say happened at around 5pm on Sunday, June 15, at the allotments near Selby Canal.
A police spokesperson said: “A group of three teenage boys, approximately 13 years of age, lured the girl to the allotments before sexually assaulting her by kissing her and trying to remove her clothing.
“The girl left the area quickly afterwards.”
Police say the boys were white, with non-local accents.
One of the suspects is described as having short ginger hair, the second suspect has short blond gelled hair and the third had black or dark gelled hair.
All of the suspects were wearing sports type clothing and are believed to have been near the canal prior to the incident.
Please email Nicola.Knowles@northyorkshire.police.uk if you have any information that could help the investigation, including the identity of the suspects.
Alternatively, you can call North Yorkshire Police on 101 and ask for Nicola Knowles, or contact Crimestoppers anonymously on 0800 555 111 or via their website.
Please quote reference 12250108245 when passing on information.
