A fourth man has been arrested after an arms cache was recovered by gardai from a warehouse.
Detectives said the seizure during a raid on a unit at Greenogue Industrial Estate, in Baldonnel, west Dublin on Tuesday foiled a n imminent gangland murder.
Three men were initially detained and gardai confirmed a fourth man was taken in for questioning as follow-up searches continued.
Among the lethal weapons seized are at least one assault rifle, a sub machine gun, several handguns and several semi-automatic pistols.
A considerable amount of ammunition was also recovered.
One line of inquiry is that the stash could be connected to the so-called Kinahan/Hutch feud which spilled over into Dublin's Regency Hotel last February - when Kinahan associate David Byrne was gunned down at a packed boxing weigh-in.