The vehicle involved was abandoned a short distance away, and it has been seized for technical examination.
Gardai in Limerick are appealing for witnesses to a hit and run incident which left one man critically injured.
Three women also suffered non-life threatening injuries following the collision in the early hours of this morning.
Henry street Gardai say the collision occurred at Corn Market Row, Limerick at 1a.m.
A man and two women were struck by a vehicle which left the scene.
All three were taken by ambulance to University Hospital Limerick.
The 33 year old man suffered serious injuries and is in critical condition.
The two female pedestrians, both in their late 30's, received non-life threatening injuries.
A 19 year old female pedestrian also presented at University Hospital Limerick, having been injured by the same vehicle - her condition is non-life threatening.
The vehicle involved in the hit and run was abandoned a short distance away, and it has been seized for technical examination.