At least 12 revellers have suffered burns from a noxious substance at a nightclub.
The incident in Dalston, east London, forced the evacuation of the venue where around 600 revellers had been at an event, it is understood, according to Daily Telegraph.
Roads were closed as emergency services, including a hazardous area response team, rushed to the scene after the alarm was raised in the early hours of Monday morning.
The London Ambulance Service (LAS) said it had taken 10 patients to hospital, while police said a further two people with similar injuries sought treatment at a hospital.
A Scotland Yard spokesman said: "Police were called to a licensed premises in Sidworth Street, Dalston, at approximately 1.10am on 17 April, after members of the public complained of a noxious substance.