Four people, three of them teenagers, have died in three separate road accidents.
In Co Tipperary, two 17-year-old youths were killed in a collision between a car and a four-wheel drive shortly after midnight at Borrisbeg, Templemore.
They were David McNamara of Knocka, Drom, Tipperary, and Colm Tierney of Erril, Portlaoise, Laois.
The passenger in the car died at the scene. The driver was taken to hospital in Limerick, where he died this morning.
Gardaí have appealed for witnesses to the crash.
In south Dublin, a 17-year-old youth died in a single-vehicle car crash in the Ballybrack area at 2.30am today.
The youth was fatally injured when the car in which he was driving collided with a tree. He was taken to Loughlinstown Hospital where he was pronounced dead a short time later.
Gardaí are asking anyone who may have seen the green Mitsubishi Colt in the Ballybrack/Shankill area before the time of the collision to contact them on 01 666 5900.
Gardaí in Limerick are investigating a fatal traffic collision in which a female cyclist was killed.
The victim was struck by a gravel truck at a construction site beside the Castletroy Park Hotel in Limerick at 4pm yesterday afternoon.
The 31-year-old woman was taken to St John's Hospital in Limerick, where she was pronounced dead.
These deaths bring to 296 the number of people who have been killed in road traffic accidents since the beginning of the year.