Gardai in Monaghan investigating an assault at Woodview, Killygowan, Monaghan have arrested a 19-year-old male this evening.
He is currently detained under the provisions of Section 4 of The Criminal Justice Act 1984 at Monaghan Garda Station.
Gardai arrived to the scene of a disturbance at 11:50pm last night and found a male aged in his late 20s unconscious on the road with injuries to his head.
He was taken by ambulance to Cavan General Hospital and later removed to Beaumont Hospital
His condition is understood to be critical.
A technical and forensic examination of the scene has been carried out.
Gardaí are appealing for any person who may have witnessed this incident or who may have any information surrounding the incident, to contact the incident room at Monaghan Garda Station on 047 77200 or the Garda Confidential Line at 1800 666 111.