Army Bomb Disposal teams were called out to deal with three separate suspect devices over the course of last night.
Two of the incidents were in Dublin and one was in Co Laois, and all required specialist units to make safe improvised explosive and suspect devices.
The first incident occurred in Killinarden in Tallaght when gardaí discovered what were described as “suspect” items when searching a property in the area.
Components for making an improvised explosive device were subsequently identified by a bomb disposal team and the scene was declared safe at 10.30pm.
A team was also dispatched to a location on the M7 near Mountrath, Co Laois at 10.45pm where a separate Garda search came across an improvised explosive device, which was later confirmed to be viable, along with a stash of firearms.
The device was made safe without the need for a controlled explosion and the scene was declared safe at 1am on Friday.
In Ballymun, a bomb disposal team was called to a private residence in the Shangan area of the suburb after the discovery of another suspect device.
Experts worked to dismantle the bomb, which was discovered to be viable, for an hour and 40 minutes before the scene was declared safe at 3.30am on Friday.
A spokesman for the Defence Forces said evidence from all three cases had been handed over to gardaí to assist with their investigations.
Bomb disposal teams have received 13 call-outs this year and dealt with four viable explosive devices following 145 call-outs last year.