Pipe bombs were planted outside two homes in separate parts of Dublin last night.
No one was injured and no damaged was caused when one of the devices exploded on Cappagh Road, Finglas.
The army bomb disposal team conducted a post blast analysis of the device and declared the scene safe at 12.35am.
Earlier, the Defence Forces were deployed to a residential area in Ardglen, Lucan, where another pipe bomb had been left on the doorstep of a house.
The scene was cordoned off by gardaí as a controlled explosion was carried out.
A spokeswoman said its remains were handed over to gardaí to assist with investigations and the scene was declared safe shortly after 1am.
Bomb disposal teams have attended 167 call-outs so far this year, including 78 viable devices and 15 post blast analysis.