Yesterday morning, officers carried out a number of raids as part of an investigation into feud-related violence in Finglas.
A close associate of gang boss 'Mr Flashy' was arrested and a firearm was seized during one search.
The raids were part of ongoing investigations into the drugs gang who are involved in an escalating Finglas feud which has seen arson attacks, assaults and one murder.
One man, aged in his 20s, was arrested and remains in custody in relation to a serious incident in January.
In a separate search gardai recovered a firearm and arrested three people, including a man in his 30s and two women in their 20s.
But now a garda spokesman has said three people arrested as part of the operation have been released without charge.
He said: "Two women in their 20s and the man in his 30s arrested following a number of searches in Finglas West, County Dublin, in which a suspected firearm was recovered, have been released without charge. Files are being prepared for the Director of Public Prosecutions.
"The man in his 20s arrested as part of this investigation is still being detained at Finglas Garda Station under Section 30 of the Offences Against Act, 1939.
"Investigations are ongoing."
Following the operation, a house in the Ratoath Road area of Finglas was also targeted in a petrol bomb attack and the incident is believed to be linked to the feud.
Speaking earlier this week the Garda Commissioner said that gardai were "concerned" about the feuding situation in Finglas.
Drew Harris said there had been threats made by rival groups who are committing serious criminality and are "hell bent" on targeting each other.
He told reporters that additional resources and armed gardai had been deployed to the area and said that the vast majority of people in Finglas reject the violence.
“Obviously, the recent murder was followed down by very serious attacks and indeed arson attacks as well.
“Finglas is supported by the national units, including the armed support unit, but also investigative resources.
“So we have put a lot of effort into making sure that we can nip this so-called feud in the bud as quickly as possible,” he said.
Last month James Whelan (29) was shot dead in the first murder linked to the dispute. Last weekend a firebomb attack was carried out on the home of an innocent female relative of Whelan.
Gardai are investigating over 70 violent incidents linked to the feuding including arsons, assaults and drub intimidation.