GARDA AND Army bomb disposal experts were last night examining the biggest primed bomb found in Dublin for decades.

It was found at a pond in the Phoenix Park in an area within a mile of important and sensitive buildings – Áras an Uachtaráin, Garda Headquarters and the US ambassador’s residence.

The bomb was found on a small island in a pond just off the road on a circuit in the park known as the two-miler, a popular route with cyclists and joggers.

The 20kg bomb was ready for use and had been built into a metal milk churn.

Security sources said a bomb of that size could blow up a double-decker bus or destroy a building and would “almost certainly” result in fatalities.

The same sources said the bomb was “way too big” and sophisticated to be used by organised crime gangs.

“This is definitely not just a big version of the pipe bombs that we’ve seen a lot of; it is a different device completely and much bigger.”

Gardaí believe the bomb was most likely left on the island in the pond for collection after being built in the Dublin area.

They are working on the theory that it is linked to dissident republicans and that it was possibly about to be moved to the North.

However, sources stressed the investigation into the matter was at a very early stage.

The device was made of home-made explosives with booster commercial explosives.

All of the wiring, detonating mechanisms and batteries needed for it to be viable were present. “It was a full bomb and it was ready for use,” said one source.

It was unclear how long the bomb may have been on the island before it was found on Monday night. However, work took place on the island within the last eight weeks and nothing out of place was noticed.

Sources said the churn that housed the device was visible from the side of the pond, adding it was unlikely it would have been there for long without being spotted.

A joint team of Garda ballistics experts and Army bomb-disposal experts is examining the device to see if they can find any clues that might link it to previous devices or to bomb-makers whose devices would be recognisable.

The Quarry Lake pond is off the North Road linking the Ashtown Gate and the main road of Chesterfield Avenue.

The churn was seen on the island by two boys fishing on Monday evening.

Gardaí were alerted and, after carrying out a preliminary examination, they called in the Army bomb team.