Up to sixty young people at a dance music event in Belfast had to be treated for the effects of drugs and alcohol on Thursday night, prompting the ambulance service to declare a “major incident”.
Fourteen of the attendants were admitted to hospital and many more were treated at the scene during an incident in Belfast, health authorities said.
The youths became ill after attending a concert at the Odyssey Arena, where Hardwell, a renowned Dutch electro-house DJ, was headlining.
Odyssey general manager Adrian Doyle said they arrived at the venue already inebriated.
The former Lord Mayor of Belfast, Niall O’Donnghaile, tweeted that he had spoken to police and an “emergency situation” had been called “to help deal with volume of people affected at the scene”. He said the youths had become ill after taking “possibly a drink or drugs or a mixture”.
Michael Copeland, an Ulster Unionist member of the Northern Ireland Assembly, said an eyewitness described the scene as "horrendous".
"It was an event for 16-18-year-olds and around 60 young people have gotten themselves into difficulties with alcohol," he said.
Mr Doyle said he was aware that a major incident has been declared by the Northern Ireland Ambulance Service outside the Odyssey Complex.
"It is our understanding that a number of patrons arriving at the Odyssey Arena to attend a concert by Dutch DJ act Hardwell have required medical attention, having already been intoxicated on their arrival at the Odyssey Complex," he said.
"These patrons were not granted entry to the Odyssey Arena, and were treated by the Ambulance Service outside. Seven patients have now been transferred to hospital by ambulance."
He said the concert continued as normal inside the arena.
"As with any concert, the safety of our patrons is our absolute priority at all times and the event control team is confident that we have sufficient staff on site to maintain a safe and enjoyable concert," he added.
Colin Neill, chief executive of Pubs of Ulster, which represents local bar owners, expressed his concern.
He stressed that the group promotes "responsible and safe" drinking, adding that "pre-loading," or drinking at home before going out, is dangerous.
"[Pre-loading] can lead to unintended consequences with people putting themselves at great risk," he said.
"Parents must stop under-18s getting access to drink and licensees should check ID and exercise extreme caution at all times.
"We urge pubs in Belfast to be extra vigilant this evening - be on the lookout for persons underage and do not admit young people possibly coming from the Odyssey who have had too much to drink."
Additional reporting by PA