Large disorder in Swindon arranged via social media
"Large scale disorder" involving 30 to 50 youths in Swindon was arranged via social media, say police.
Wiltshire Police officers were called to a field near Haydon End on Wednesday following reports of youths congregating in the area.
A teenager sustained a knife wound across the stomach which required hospital treatment.
A 16-year-old boy was arrested on suspicion of grievous bodily harm and released on bail pending enquiries.
Det Sgt Liz Coles said: "We are treating this incident very seriously and we believe that this could escalate.
"There have already been reports of further incidents connected to this and we are putting sufficient resources into targeted patrols to ensure there are no further incidents of disorder or violence.
"Anyone using a social networking site to arrange a fight should be warned that we will be able track you down by your electronic footprint and that this is a serious offence on its own."