Dance trio Swedish House Mafia's concert in Ireland on Saturday (07Jul12) was marred by violence after a knife attack left nine gig-goers injured, according to reports.
The DJ supergroup, comprising of producers Axwell, Steve Angello and Sebastian Ingrosso, headlined Dublin's Phoenix Park, but tragedy struck during the show.
Police believe one man stabbed up to four revellers, and that other crowd members sustained injuries during incidents involving knives and broken bottles.
A 23-year-old man has been charged in connection with an incident at the show and was due in court on Monday (09Jul12).
A spokesperson the Irish police said the officers received reports of a "significant number" of random unprovoked attacks at the show and are hunting those involved.
Concert promoters have handed Cctv footage to police, and officials at Ireland's Health Service Executive have now launched an investigation into the incidents.