Motorists are being advised to avoid the main Derry to Buncrana Road in the Whitehouse area due to an ongoing security alert.
The main thoroughfare has been closed by police who are carrying out a search operation after a report of suspicious activity in the area.
Army bomb disposal experts are at the scene.
The Buncrana Road is closed from Skeoge Road to Templemore Sports Complex.
Minor roads in the area, including Whitehouse Road, Coshquin Road and Groarty Road are also sealed off.
A police spokesperson has advised motorists to seek alternative main routes for their journeys.
