Gardaí in Limerick are investigating a serious assault on Maiden Street, Newcastle West on Saturday evening.
A 21 year old man has been taken to University Hospital Limerick where he remains in a critical condition following the incident which happened around 5pm.
The scene is currently being preserved and Gardai are appealing for witnesses.
A man in his twenties was arrested at the scene and is currently detained under Section 4, of the Criminal Justice Act, at Newcastle West Garda Station.