Gardaí said today that they are keeping an open mind after dissident republican terrorists claimed they murdered a man at a Dublin hotel during a weigh-in for a boxing match.

The Continuity IRA claimed responsibility for gunning down David Byrne, 33, from Crumlin, and wounding two others at the Regency Hotel on Friday afternoon.

The scene after the shootings at the Regency Hotel on Friday afternoon as paramedics remove a man injured in the attack. Picture: Cascadenews.co.uk

The splinter group said it had been retraining and re-arming in recent years and that it sent a six-strong gang – three armed with Kalashnikov assault rifles and dressed in Swat team uniforms and helmets – to target the criminal.

It claimed that Byrne was singled out in retaliation for the killing of Alan Ryan in Dublin in September 2012 – a leader of a faction of the Real IRA in north Dublin.

“This will not be an isolated incident. CIRA units have been authorised to carry out further operations. More drug dealers and criminals will be targeted. CIRA will carry out further military operations,” the dissidents claimed.

In a statement the Garda press office said: “Gardaí are aware of the recent statement to the media and are keeping an open mind in relation to the criminal groups involved as part of their investigations.”

Senior gardaí had ruled terrorism out in the aftermath of the attack and while the claim for responsibility followed a path well worn by terrorists of contacting a respected journalist and the BBC in Belfast with a code word, it is difficult to verify it.

Vincent Kearney, BBC’s Northern Ireland Home Affairs Correspondent, who received the statement of accountability from the CIRA, spoke to The Sean Moncrieff Show on Newstalk Radio today.

“This (the claiming of responsibility) came in a statement given to me verbally...it came in the form of a source I would regard as credible,” he said.

“What happens is that you are given a statement verbally, that you would then write down and pass on.

“There was a code word associated with it...but what was unusual was…it was not one which I have come across before… as the continuity IRA has been largely inactive for quite a period of time.”

He added: “‘The CIRA claimed the attack was revenge for the murder of Alan Ryan (of the Real IRA) four years ago.

“His faction within the RIRA was engaged in a long running feud with gangland criminals. CIRA said they were not going to stand back and allow drug dealers and criminals to target Republicans.

“They were careful in their choice of language. We know that the CIRA have been accused by the Gardaí and the PSNI of being involved in a wide range of activities, including drug dealing

“So this is them trying to set themselves up as the protectors of the people.”

Detectives are running a number of lines of inquiries including that the discriminate attack, which targeted Byrne and two others who remain in hospital, was an escalation of a dispute between drugs gangs based in Dublin and the Costa del Sol.

There is further speculation that the gunmen were guns for hire to avenge the murder of Gary Hutch in Marbella last year or if the claim is deliberate misinformation by gangsters or if dissidents are so heavily embroiled in the drugs trade that they have taken sides in a dispute.

About 300 people were in the hotel when the gang struck, including families with children, boxing fans and a small number of journalists and photographers.

They were attending a weigh-in for a title fight billed Clash Of The Clans between Jamie Kavanagh and Antonio Jao Bento which was due to be broadcast by Boxnation and was subsequently cancelled.

Some journalists and photographers from Irish newspapers were in the grounds of the hotel anticipating figures from Dublin’s criminal underworld would be present.

Amateur video footage of the weigh-in was posted online showing the horror unfold.

Byrne’s body was seen by a number of people slumped against the reception desk “riddled” with bullets while witnesses described seeing two other gunmen carrying handguns, one dressed as a woman with an auburn wig and the other wearing a beige flat cap and tracksuit.

Photographs of the gang have been published but gardaí requested that media pixellate the faces of two of those not in the Swat style uniforms.

Units of the Garda’s armed Emergency Response Unit were sent on patrol in certain parts of Dublin over the weekend with a number of high profile checkpoints set up in the wake of the murder.

No arrests have been made.

And in the heat of a general election campaign, Justice Minister Frances Fitzgerald came under pressure to explain why journalists took the initiative to stake out the hotel for underworld figures but Garda detectives were not there.

“The answer the Garda Commissioner (Noirin O’Sullivan) has given ... there was no operational intelligence in relation to this event,” she said, insisting it was not a resource issue.

James McGettigan, managing director of the Regency, also revealed it took three 999 calls before he got an answer, only to be diverted to a second office.