They were arrested in Longford.
Gardaí have arrested four people in the midlands following violent disorder.
The incident took place in Loughnaneane Park in Roscommon, on the 27th of July.
Gardaí carried out searches at two residential properties in Longford and arrested a man in his 30's, a woman in her 20's and two juveniles.
They are appealing to anyone who witnessed the incident to come forward, including anyone with camera footage from the Park.
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