As many as 60 concert-goers are recovering this morning after being treated by the emergency services for adverse effects related to drugs and alcohol at a concert by Dutch electro-house DJ Hardwell in Belfast's Odyssey Arena yesterday evening.

The emergency services declared a "major incident" after the scale of the medical issues - apparently caused by a drink and drugs cocktail - became apparent. As quoted by The Independent, former Lord Mayor of Belfast Niall O'Donnghaile said that the "emergency situation" was declared "to help deal with [the] volume of people affected at the scene".

Seven people were taken to hospital but the police have said that none of them are considered to be in a serious condition.

Adrian Doyle, general manager of the Odyssey Arena, said that the problem became apparent almost immediately upon the arrival and that "these patrons were not granted entry to the Odyssey Arena".

"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", commented Doyle.

Speculation online (which we have been unable to corroborate) suggests that a toxic batch of ecstasy tablets were the cause of the illnesses and that the group of youths who became ill all arrived at the arena on the same bus.

Hardwell will play in The O2 in Dublin this evening and it is understood that the concert will go ahead as planned without any special arrangements.