A number of prisoners were injured during a protest at Cloverhill prison and some damage was caused to the building itself.
It started when a large group of prisoners refused to leave the B Yard at Cloverhill prison this morning and return to their cells.
Two prisoners even managed to get onto an adjoining roof top.
Prison management tried to bring the situation to an end through negotiation but things took a turn for the worse and one prisoner was beaten by some of the other inmates.
Around 15 prisoners were then removed from the yard and a number were injured.
The Irish Prison service says some damage was also caused to the prison itself and the matter will now be subject to an internal investigation as well as an investigation by Gardai.
