Army bomb disposal experts made safe a device discovered by garda during a search of a property in west Dublin last night.
The device, described as a pipe-bomb, was discovered in the upstairs room of a house in Wheatfield Grove area of Neilstown. A number of items have been retained for forensic examination.
The residents of the house, a 17-year-old youth and a 23-year-old woman were taken into custody although the woman was later released without charge.
The young man is being detained under section 30 of Offences Against the State Act at Ronanastown Garda station.