Army bomb disposal teams dealt with two suspect devices last night in Dublin and Tullamore.
A suspect package was found under a railway bridge on the outskirts of Tullamore, Co Offaly at about 7pm.
The Army bomb disposal team made the device safe at the scene.
A Defence Forces spokesman said it contained explosives and had the "potential to explode at a later time".
It is thought that the device may have been kept at the location with a view to it being used at a later date.
The all clear was given at 8.50pm.
A second suspect device was discovered at Ballyowen Park off Ballgaddy Road, Clondalkin shortly after 9pm last night.
The Army bomb disposal unit carried out a controlled explosion on the package.
Further examination of the device at the scene revealed that it did not contain any explosives and the all-clear was given at 11.45 pm.
The remains of the two devices were handed over to gardaí.
