Four men have been arrested in Dublin's north inner city for conspiracy to murder as part of an investigation into the feud between the Hutch and Kinahan crime gangs.
A firearm and silencer have also been seized by gardaí.
The four men, aged 23, 35, 37 and 38, were arrested in coordinated interceptions.
Armed officers from the Emergency Response Unit stopped a car on Philipsburgh Avenue in Fairview and arrested two men at around 8pm.
The two other men were arrested on the southside of the city.
All four are well-known to gardaí.
One is a senior figure in the Kinahan gang and a convicted drug dealer, while two others are suspected gunmen from west Dublin.
The two men from west Dublin are suspected of having been hired as hitmen by the Kinahan gang.
One of that pair was released from prison earlier this year after serving a sentence for firearms offences. The other was the victim of a gun attack a few years ago.
The fourth man is also an associate of the Kinahan gang with more than 50 convictions, including for bomb and firearm offences.
The arrests have been described as significant.
Gardaí say they believe their actions have prevented an attack on an associate of the Hutch gang who lives in Marino in Dublin.
The man was aware his life was under threat.
The four men are being held under anti-gang legislation and can be questioned for up to seven days.
Assistant Commissioner John O'Driscoll said the arrests "represent a significant additional achievement in An Garda Síochána's ongoing and unrelenting effort to tackle organised crime and, in particular, the total disregard for human life exhibited by the criminals involved".