Monaghan pensioner Patrick McGeough (79) has died, along with a man in his 40s in separate road crashes.
There were three serious road crashes across Northern Ireland within 12 hours.
Fermanagh pensioner Patrick James McGeough has died following a road crash on a cross border route, while a man in his 40 has died in a crash in Londonderry.
Two men have died and a third left injured in a weekend of carnage on the roads in Northern Ireland.
The PSNI say the man who died in a crash on the A3 Cavan Road, near Newtownbutler, on Saturday was 79-year-old Patrick James McGeough from the Monaghan area.
A man aged in his 40s has died following a road crash on Londonderry just after midnight on Sunday and one person was injured in another crash on the Ards Peninsula in Co Down on Saturday.
In the Derry crash a man aged in his 50s and a woman aged in her 50s were taken to hospital for treatment to their injuries which are not believed to be life threatening.
Inspector Smyth said a silver coloured Ford Ka and a grey coloured Peugeot 308 were involved in the incident.
"I would ask anyone who may have witnessed the collision or the cars in the area to contact Strand Road Police Station or the Collision Investigation Unit on the non-emergency number 101," he said.
The Clooney Road re-opened to traffic on Sunday afternoon.
The crash in Fermanagh took place on the A3 Cavan Road close to Newtownbutler on Saturday afternoon.
The road has been closed on both sides of the border.
Police can confirm that a man has died following an rtc on the A3 Cavan Road, near Newtownbutler, this afternoon. The road remains closed.— PSNI Road Policing (@PSNITraffic) September 3, 2016
A man in his 70s died in the crash. No further details have yet been released.
Motorists are advised to expect delays in the area and to find an alternative route if possible.
Meanwhile in Co Down one person has been injured in a serious road crash.
Police said the crash close to Ballywalter on the Ards Peninsula happened at about 4.50pm on Saturday afternoon on the Dunover Road.
It is understood that the car caught fure. A local farmer went to the aid of the driver.