The Army Bomb Squad was called out to a major An Post sorting office in Dublin after staff intercepted a suspicious package.
Gardaí in Clondalkin were alerted to an incident at the Dublin Mail Centre on the Nangor Road at about 4pm on Monday.
The Defence Forces Explosive Ordnance Disposal (EOD) team attended the scene. A bomb disposal robot has been deployed to assess the package and detonate it if deemed necessary.
A garda spokesman said the Nangor Road and Parkwest business park was closed as a result of the operation and diversions are in place.
Following an investigation by the EOD team it was confirmed the suspicious package was empty, and units confirmed the area was safe, according to a Garda spokesman.