Swindon CID, investigating what it describes as large-scale disorder and serious assault in a field close to Haydon End, say they know who the youths involved are.
A 16 year old boy has been arrested on suspicion of grievous bodily harm in connection with an incident in north Swindon.
Police say a teenager sustained a knife wound across the lower stomach which required hospital treatment, when between 30 and 50 youths gathered in a field close to Haydon End in Swindon on the evening of Wednesday 6 March.
The arrested youth has been released on conditional bail pending further enquiries.
Police in Wiltshire say between 30 and 50 youths gathered in a field in north Swindon to commit large-scale disorder and serious assault.
Officers have told ITV News Westcountry that they believe it was arranged through social media, such as social networking sites.
One teenager was treated in hospital for a knife wound across the lower stomach during the incident in a field close to Haydon End on the evening of Wednesday 6 March.
Wiltshire Police say youths were seen congregating in and around several streets including Prospero Way, Havisham Drive, Hardy Close and Mazurek Way.