Gardaí are appealing for information and witnesses
Four men have died in fatal road traffic accidents overnight.
Two men died in Donegal after the car they were driving collided head-on with a van at around 4.45am.
It happened on the inbound carriageway of the N13 dual carriageway at Trimragh in Letterkenny.
The two men, understood to be be aged in their late teens and 20s, were pronounced dead at the scene.
The driver of the van was taken by ambulance to University Hospital, Letterkenny. His injuries are not thought to be life-threatening.
Garda forensic collision investigators have been requested to examine the scene and the local coroner has been notified.
Meanwhile, gardaí in Kilcock are investigating a two-vehicle collision in which a man in his 20s died in Kildare.
He was fatally injured when the car he was driving collided with a truck on the R407 Clane to Kilcock Road near Baltracey at around 11.30pm last night.
He was pronounced dead at the scene and his body removed to Naas Hospital.
The driver of the truck was taken to Blanchardstown Hospital with what are described as minor injuries.
And gardaí in Meath are appealing for witnesses to a collision in Dunboyne.
A 42-year-old man was seriously injured when the car he was driving collided head-on with a second car at around 8.50pm.
It happened on the R152 Dunboyne to Maynooth Road at Castlefarm near Dunboyne.
He was taken by ambulance to Connolly Hospital Blanchardstown, where he was later pronounced dead.
He was the sole occupant of the car.
The driver and four passengers in the second car were also removed to hospital - their injuries are not believed to be life-threatening.
The scene is preserved while garda forensic collision investigators conduct an examination.
Anyone with information on any of the incidents is asked to contact gardaí, or the Garda Confidential Line on 1800-666-111.