A crime scene investigation team are carrying out an examination at a handball alley in Michael Street in Kilkenny City where an 'organised fight' between secondary school students took place yesterday.
The scene is cordoned off and officers are combing the area for evidence.
Approximately 200 young people attended the fight, which was organised on social media.
A teenager was treated at St Luke's Hospital. A full garda investigation has been launched.
It is understood that students from two schools in the city attended the fight and that both schools are co-operating fully with gardaí.
Anyone who witnessed the incident is asked to contact Kilkenny gardai on (056) 777 5000.
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