Fire crews and personnel from 10 different stations are continuing to battle a blaze near Poyntzpass.
A shed has been gutted and firefighters are still on scene attempting to douse the flames.
The PSNI stepped in and closed the Lisraw Road to assist with traffic control.
The fire broke out earlier this afternoon, with appliances and personnel on scene from before 1pm.
A spokesperson from Northern Ireland Fire and Rescue Service said: “Fire Appliances from Portadown, Armagh, Banbridge, Newry, Rathfriland and Lurgan, along with specialist appliances from Knock, Pomeroy, Warrenpoint and Lisburn are in attendance.”
Firefighters have been using an extendable ladder to try and tackle the fire from above.
Meanwhile, the PSNI are advising motorists to seek an alternative route as the operation continues.