A suspect device has been discovered at the rear of a house in a Cavan housing estate.
The device was found before 6pm this evening and Garda were notified.
A number of homes have been evacuated in the Lakeview Estate.
Gardaí are at the scene and are awaiting the assistance of the Army Bomb Disposal Unit.
Detectives anticipate that residents will remain out of their houses until 11pm tonight, at the latest.