The N53 Castleblayney to Dundalk Road is closed this morning due to a road traffic collision in the vicinity of Toome Football Field.
Gardaí have confirmed that the road will be closed both sides of the border for the foreseeable.
In a statement to Northern Sound Gardaí said, "Gardaí and emergency services are currently attending the scene of a road traffic collision that occurred at approximately 6:45am today, on the N53 in the Castleblayney area of Co Monaghan.
"This road is currently closed while the scene is being attended with diversions in place."
Motorists are asked to avoid the area and seek an alternative route for your journey.