A PIPEBOMB exploded outside a house in north Dublin, blowing out a window.
The blast was at Apollo Way in Coolock in the early hours of this morning.
No one was injured and no arrests have been made.
Sources say that detectives are investigating if a notorious local gang is responsible for the bomb attack.
The army bomb disposal team was called, but specialist gardai had already dismantled what was left of the bomb by the time the army unit arrived.
A senior source said: "Gardai are extremely concerned about the growing use of pipebombs by criminal gangs across the city.
"It is only a matter of time before someone gets seriously injured," the source added.
"Similarities have been noticed in relation to many of these devices.
"This means investigators believe a maximum of around four groupings are making these bombs, including Traveller criminals and dissident Republicans."