Two men in their 20s collapsed as clubbers rushed to escape the Easter event at the trendy Mangle venue in Hackney, east London.
Others grabbed bottles of water to pour over friends whose faces had been burned by the corrosive liquid.
About 200 revellers fled the club before the emergency services arrived.
Another 400 were evacuated soon after and police closed off surrounding roads.
Emergency services at the scene after an attacker sprayed acid into a crowd leaving a nightclub
One witness said: “It was like war. The police were everywhere.”
It was like war. The police were everywhere
The two men were in a serious but stable condition. Eight others were treated before being taken to hospital and two more attended A&E.
The attack at the Mangle venue in Hackney, east London, left 12 people injured
No arrests were made. Launching an investigation, Scotland Yard said the attack – which is not thought to be gang-related – was triggered by a row between two groups at about 1.10am.
Meanwhile, a 31-yearold man is in a serious but stable condition in hospital after being attacked with an axe at the Bijou Club in Manchester city centre.
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