North Yorkshire Police are appealing for witnesses and information about an altercation that occurred at Wigginton Playing Fields, Church Lane, in York.
It happened between 9.30pm and 10pm on Monday 15 July, during the altercation a 17-year-old boy was punched in the face.
A 17-year-old boy has been arrested in connection with the incident and bailed pending further enquiries.
Please email sophie.wilson1@northyorkshire.police.uk if you have any information that could help our investigation.
Alternatively, you can call North Yorkshire Police on 101, and ask for PC Sophie Wilson, or contact Crimestoppers anonymously on 0800 555 111 or via their website.
Please quote reference 12240126082 when passing on information.