Gardaí received reports of a suspicious device at a location on Plantation Road in Monaghan town at approximately 10:10am this morning.
A cordon has been established and the services of the Army Explosive Ordnance Disposal (EOD) Unit have been requested to deal with ongoing situation.
Nearby buildings have been evacuated and the building site of the new Peace Campus in the town.
Gardai are at the scene of the suspicious device find which Northern Sound understands is old grenade.
The device was found alongside an old wall that runs along the old Garda barracks in the town.