A prison officer was treated in hospital after he received an injury to his hand when he intervened in a dispute between two inmates at Portlaoise Prison.
The incident happened on Friday when a fight broke out between two inmates, one of whom was using an improvised weapon.
As the officer attempted to break up the fight he received a cut to his finger.
He was treated in Portlaoise hospital a short time later where it is understood he given a number of stitches.
The Irish Prison Service said disciplinary action will be taken agains the inmates involved in the incident and that the gardaí have been informed of the matter.
