Two prisoners remain on a jail roof after a protest saw at least one inmate stabbed.
The violence broke out in an exercise yard at Cloverhill in west Dublin when a group of about 15 men refused to return to their cells at around lunchtime.
It is understood goalposts in an area next to the prison’s B division were ripped from the ground and smashed before being used to rip down razor wire and clear access to a roof.
They were also used as makeshift weapons when riot squad officers were called in to restore order after several hours of negotiations failed.
The Irish Prison Service said two men climbed on to the top of three-storey accommodation, about 30 feet up, and refused to come down after the protest began.
A security and observation hut at ground level in the yard was also destroyed in the disturbance.
About 60 prisoners were in the exercise area when the protest broke out but only about 15 were initially believed to have been directly involved in the stand-off with prison officers.
The Irish Prison Service said the governor of Cloverhill, Ronan Maher, ordered its riot trained officers, known as control and restraint teams, to move into the yard to remove the ringleaders after at least four hours of talks.
A spokesman said a number of prisoners were injured during the clearance operation while it is understood some inmates used bits of the broken goalposts and materials from the smashed hut to attack officers.
Several ambulances were called to the prison to treat the injured.
One inmate was said to be seriously injured in a suspected stabbing after being attacked by a number of fellow inmates who were involved in the protest.
The Irish Prison Service said efforts were made by prison management to resolve the incident through negotiation and while the yard has been cleared and relative calm restored, two inmates have refused to come off the roof.
“The matter will now be subject to an internal investigation and an investigation by An Garda Siochana,” a spokesman said.
“The Director General (Michael Donnellan) would like to commend the management and staff for the very professional manner in which they managed this incident.”
Cloverhill is part of the west Dublin prison campus which also incorporates Wheatfield and it is primarily used to house prisoners who are being held on remand.
Meanwhile, the Irish Prison Service said 33 staff from its escort section are alleged to have turned up for duty without driving licences in wildcat industrial action.
In a statement the authority said management were told that they had “forgotten” their documents, disrupting transport for inmates to courts.
“The Irish Prison Service views this action as wildcat industrial action by individual staff which is in total contravention of all industrial relations practices and procedures. Such action represents a serious breach of discipline and will be dealt with under the appropriate disciplinary procedure,” a spokesman said.
Escorts to the Criminal Courts Complex were delayed but the prison service insisted every prisoner who was due to attend court had arrived by 1.30pm or was en route.
It is understood the dispute follows attempts to introduce new rosters for the escort teams to meet changes to court sittings.
The Irish Prison Service said it understood an agreement had been reached last week.