The Garda Commissioner says a vicious brawl at Dublin Airport was fuelled by drink as he defended the policing response.
Drew Harris explained that a number of men were refused travel after the incident on Tuesday afternoon at Terminal 1.
Footage which went viral shows large groups fighting for a number of minutes before gardai were on the scene.
Read More: 'Vicious' fight in Dublin Airport leaves man in hospital and another arrested
Harris told how officers had intervened in an initial incident before another row broke out afterwards in a different area.
He did not know the response time, but will be briefed on it to get more details of what exactly happened.
The Garda chief said: "It's regrettably a violent incident which seems to have been fuelled by drink.
"Then we did obviously deploy sufficient resources to make sure that order was resolved and indeed then a number of passengers were refused flight."
He added: "Well, (gardai) were responding to that, and I understand that the initial incidents had moved then to the end of the pier.
"And gardai were responding to other parts of the airport. So our response was on its way to bring a sense of order and an investigation is now under way in various offences of assault."
Harris was speaking to reporters ahead of addressing the Garda Representative Association's conference in Westport, Mayo on Wednesday morning.
Justice Minister Helen McEntee also attended and condemned the incident.
She said: "I've seen the footage. It's absolutely not acceptable, people queuing to go on their holidays and a lot of children around.
"They don't need to see this type of behaviour. There's ongoing investigations underway.
"I've full support in the gardaí to carry out that investigation."
The incident came just two weeks after Minister McEntee opened a new garda station at the airport.
The footage shows two men exchanging blows in the airport as other passengers look on.
A third man joins in and doles out a flurry of punches which knocks one of the men to the ground.
The man on the ground is kicked in the head until he is unconscious. A number of people then drag him away from the others.
The horrifying incident went on for at least two minutes and 10 seconds. Three flights departing the airport were delayed but it is unclear if this is related to the fracas.
The incident saw one man hospitalised while another man, in his 20s, was arrested.
A garda spokesman confirmed: "One man has since been taken to Beaumont Hospital where he is receiving treatment. One man (20s) was arrested and is currently detained at Swords Garda station."
A Dublin Airport Authority spokesman said: "daa can confirm that an incident occurred at Dublin Airport this evening which was attended by An Garda Siochana.
"As this incident is subject to a police investigation, we are unable to comment further at this time."
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