A 13-year-old boy has been arrested on suspicion of raping a teenage girl.
Police said the girl had been raped in Rye Park, off London Road, High Wycombe, at about 15:00 BST on Monday and were appealing for witnesses.
The boy, from Buckinghamshire, was arrested on suspicion of rape and has been released on conditional bail.
Det Insp Michael Anderson said the attack was believed to be an isolated incident with no wider risk to the public.
"This is naturally a distressing incident for the victim, and it will understandably cause concern in the local community," he said.