Channel 4 News' technology journalist Benjamin Cohen was at the event and said hundreds of revellers were kept inside the club while police investigated the incident.
Cohen told The Daily Telegraph:
"Everyone tried to leave at the same time but the organisers weren't geared up for it and there was a huge rush to get to the cloakroom.
"People were crying and quite a lot were being sick, whether from the blood or the alcohol. A lot of people here were teen users of BlackBerry who don't seem to have had a free drink before."
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