The A1 Newry Bypass has been closed due to the discovery of a suspicious object this morning.
The road has been closed from the Carnbane Roundabout to the Forkhill Road Roundabout.
The Camlough Road has also been closed in both directions either side of the flyover.
A PSNI spokeswoman said all Dublin-bound traffic is being diverted through Newry City and motorists should expect delays.