Gardaí have begun an investigation into the disturbances at Mountjoy prison yesterday, which left five prison officers and two inmates injured.
The incident began yesterday afternoon when when around 50 prisoners barricaded themselves into a recreation room in D Wing.
A stand-off developed but two hours later prison officers in full riot gear moved in and the protest was forced to an end.
The protest is understood to be related to prisoners' mounting anger at tough new security measures put in place to prevent the smuggling of drugs into the jail.
Overcrowding has been an issue at the prison which was designed to hold 420 and currently has almost 600 inmates, but the prison service said the protest was not about conditions.
However, the Prison Officers Association (POA) is citing over-crowding as a "contributory factor" to the incident, saying it was "deeply concerned" and had repeatedly warned management about the potential for violence in Mountjoy and other prisons.
The orgnaisation is seeking a meeting with senior management in the Irish Prison Service.