The Army was called to deal with a hoax nail bomb that was found under a parked car in Crumlin, south Dublin last night.
An Army spokesman said the device, which was found on Kildare Road, consisted of nails, screws and a powdered substance packed into a small tube.
It contained no explosives and a controlled explosion was not required, he said.
The area was sealed off and houses were evacuated for a number of hours.
The remains of the device are being forensically examined by gardaí this morning.
On Wednesday night, a pipe bomb exploded outside another house on Monasterboice Road in Crumlin. It was thrown from a passing car into the front garden of the house at about 11pm and exploded underneath the living room window.
It was the first time that an explosive device used by gangland criminals had exploded. There were no injuries.
The incidents are believed to be linked to a row between criminals from the area.
Gardaí also seized component parts for 20 devices last week in Tallaght, Dublin.
The Garda Commissioner, Fachtna Murphy, and Minister for Justice Brian Lenihan yesterday expressed concern at the growing use of pipe bombs by criminal gangs. Gardaí are waging a "relentless war" against organised gangs, Mr Lenihan said.