Police have sealed off part of the Buncrana Road in Derry.
The road has been sealed off at the Collon junction.
Army Technical Officers (ATO) arrived at the scene around an hour ago, and it is understood that a house at Maybrook Terrace is the focus of the investigation.
Police have confirmed that a number of items were taken away for further information after a house was searched shortly after 9.15am this morning.
Traffic diversions are in place.
ABOVE - Army Technical Officers (ATO) pictured arriving at the scene earlier.
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