The victims include a 10-year-old boy.
Three young people have died in two separate traffic incidents in Limerick and Carlow.
Two of the victims died following a crash in Limerick between a cyclist and a vehicle.
The male cyclist, believed to be in his 20s, and the driver of a car who is under 18, both died when they collided on the Hyde Road in Roxboro around midnight.
A male teenage passenger in the car has been hospitalised.
In a separate incident a 10-year-old boy who was hit by a jeep in Carlow yesterday has also died.
The incident occurred at around half past 1 yesterday afternoon the 10 year old boy was out cycling his bike when hit by a jeep.
He was airlifted from the scene to Temple Street Children’s Hospital in a critical condition, but has since passed away from his injuries.
Gardaí are appealing for any witness’s to come forward, particularly any road users who may have dash cam footage.
Anyone with information is asked to contact Carlow Garda Station or the Garda Confidential Line