A disturbance involving 60 prisoners at Cloverhill Prison was brought to an end by staff in riot gear on Wednesday evening. Gardaí have launched a criminal investigation in to the distubance that saw at least one prisoner held hostage and seriously assaulted and 10 others injured and hospitalised.

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 of the protest after at least four hours of talks.

The order was made after a prisoner who was being held hostage was set upon by a group of others.The prisoner was beaten and suffered a broken arm before being slashed in the face with a shiv, or makeshift knife.

Security sources said one of the leaders is in prison serving sentences for violent crime. He is a member of a notorious crime family and had previously been involved in extreme violence, including in the prison setting.

Two prisoners who had climbed onto the roof of the jail were still engaged in that protest last night, but an estimated 60-strong group that had refused to leave an exercise yard had been returned to their cells.

Separate to the Garda investigation, the events were also the subject of an internal prison service inquiry.

Trouble flared when an estimated 60 prisoners taking a recreational break in the exercise yard in the B division of the jail refused to leave and return to their cells. 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 and refused to come down after the protest began. The section of roof where the men remained last night is sloped and approximately 40ft high.

It is unclear what the protests were about, but some staff believed they were taking issue with “the general conditions”.

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.

Staff from adjoining Wheatfield Prison, which is on the same campus as Cloverhill in Clondalkin, were drafted in as emergency back-up.

During the protest some prisoners in the yard vandalised prison infrastructure and a security and observation hut in the yard was destroyed.

They then engaged in a group assault on a prisoner they had taken hostage, forcing an immediate intervention by staff.

When the prison service’s riot squad was ordered into the yard, the group of 10 to 15 ring leaders refused to move and their compliance was forced. In the course of clearing the yard, 10 prisoners were injured. They were hospitalised, as was the prisoner who was taken hostage and subjected to the group assault.

A statement from the Irish Prison Service said the control and restraint teams had only been deployed when efforts to negotiate a peaceful end to the disturbance were not successful.

Prison service director general Michael Donnellan commended “the management and staff for the very professional manner in which they managed this incident”.