A man was stabbed at a Hertfordshire music festival in August.
According to Hertfordshire Constabulary, the incident took place at around 8.40pm on Sunday, August 14, at the Herts County Showground off Redbourn's Dunstable Road.
A "large altercation" reportedly broke out, in which a man in his 30s received a stab wound.
He was taken to hospital and has since been discharged.
Police officers in the county have now appealed for witnesses and information related to this incident.
DC Adam Haines, investigating, said: "Though the injury was serious and left the victim requiring hospital treatment, thankfully it was not considered life-changing or life-threatening.
"Our investigation has been progressing, but we still believe there are other people we have not spoken to, who may have information that can help us further.
"This was a busy event, with an estimated 4,000 people in attendance, and as such I believe that several people may have witnessed this incident taking place or have information or video footage that could assist with our investigation.
"If you do, please get in touch as soon as possible.
"Any information, even something that may seem relatively minor or insignificant, could be key to progressing our investigation."
Information can also be reported via the Hertfordshire police website (www.herts.police.uk/report), or by calling the police's non-emergency number 101.
Anonymous information can also be given by contacting the CrimeStoppers charity on 0800 555 111.
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