Diversions are in place on the N2 outside Castleblayney due to an overturned lorry.
No injuries have been reported to the incident that has occurred in the past hour at the Tullyvin Roundabout.
This section of the road is currently closed.
Gardaí are at scene and detour signs are in place.
Traffic wishing to proceed southbound are being diverted into Castleblayney Town, and then being diverted onto the N53 - Dundalk Road.
Northbound traffic heading from Carrickmacross to Monaghan can still proceed on the N2.
Local gardaí add that traffic is very heavy and have advised motorists to avoid the area for next hour or so.