Detectives have recovered a knife after five teenagers suffered slash wounds during a vicious row at Ireland's biggest music festival.
One of the men, a 19-year-old from Co Tyrone, is being treated in hospital after being stabbed in the neck during the incident at Oxegen in Punchestown, Co Kildare.
It is understood his injuries are not life threatening. The four other young men were treated on site for slash wounds to their faces and arms.
Three of them are from Co Derry and the other is from Co Wexford.
No arrests have yet been made.
The row erupted at section B23 of the festival's blue campsite shortly after 4am.
A Garda spokesman said all involved were aged 18 or 19 years. The families of the injured men have been notified.
The man who was stabbed in the neck had to be taken to Tallaght General Hospital, in south Dublin.
Gardai appealed for anyone who witnessed the incident or who has any information to contact them.
Up to 80,000 are expected to attend the three-day festival. Acts include Beyonce, Coldplay, Foo Fighters and Paolo Nutini.