The Glenshane Road in Claudy was closed last night following the discovery of a suspicious object in the area.
Diversions were put in place and motorists advised to avoid the area and seek alternative routes.
There are no further details or updates on the security alert.
Subscribe or register today to discover more from DonegalLive.ie
Buy the e-paper of the Donegal Democrat, Donegal People's Press, Donegal Post and Inish Times here for instant access to Donegal's premier news titles.
Keep up with the latest news from Donegal with our daily newsletter featuring the most important stories of the day delivered to your inbox every evening at 5pm.