Three people have been killed in a road crash in Co Louth in the early hours of this morning.
The two-vehicle collision occurred at Carrickarnan on the N1 at around 2.15am.
A fourth person, a man in his early 20s, was taken to Our Lady of Lourdes Hospital in Drogheda, where his condition is described as serious.
Emergency services spent the day at the scene at Carrickarnan on the N1, the Dublin to Belfast Road.
A red hazard triangle marked the spot where the two vehicles are believed to have collided.
Car debris littered the road.
Several hundred metres away one of the vehicles involved was covered with a tarpaulin.
It is understood two of the victims, a woman in her 80s and her son in his 50s from Bessbrook in Co Armagh, were travelling in this car.
The second vehicle crashed into a ditch along the side of the road.
One of its occupants was killed.
Gardaí are examining the possibility that some of the occupants in one of the cars involved may have left the scene on foot.
There were long tailbacks throughout the day as the road was closed in both directions and diversions put in place.
Gardaí are appealing for information and particularly to road users who may have camera footage to make it available to them.
Anyone with information should contact Dundalk Garda Station on 042-9388400, the Garda Confidential Line on 1800 666 111 or any garda station.
Separately, a man in his 20s has died after he was struck by an articulated lorry at around 11.15am on the N54 between Monaghan and Clones.
He was taken to Tallaght University Hospital with serious injuries, but later died there.
The lorry driver was not injured.
Diversions are in place and gardaí are appealing to any motorists who may have travelled the road between 11am and 11.30am or may have dash-cam footage to contact Monaghan Garda Station on 047 77240, the Garda Confidential Line on 1800 666 111 or any garda station.
The deaths bring to six the number of people who have been killed on Irish roads since yesterday.
A man and a woman, both in their 60s, were killed in a collision in Co Cavan.
The collision between a car and 4x4 vehicle occurred on the N55 at Ballinagh yesterday evening.
