MORE than 20 people were arrested by gardai at a Calvin Harris concert tonight.
It is understood that the arrests were made outside the O2 as huge numbers of revellers gathered before the act was due to begin.
Gardai said there was a large scattering of people outside the venue, and reports say six people were arrested for being drunk and disorderly and more for drugs offences. Another was arrested for assault.
At least one garda officer and a security officer suffered injuries during assaults at the event. The garda suffered a gash to the forehead.
Gardai made a number of arrests as ugly scenes marred the music concert.
Dozens of people were escorted from the premises in one 30 minute period while a number of arrests, witnessed by the Herald, were made for public order offences.
One hand-cuffed reveller shouted and resisted garda efforts to detain him while others went more quietly. Some had bloodstains on their clothes.
Several concert goers were removed but continued to wait at the gates remonstrating with stewards. The drink fuelled chaotic scenes at last night's Calvin Harris and Dj Tiesto concert come two years after similar events marred a Swedish House Mafia concert at the Phoenix Park.