Detectives investigating after a noxious substance was sprayed inside a Hackney nightclub are searching for those wanted for questioning in relation to the attack.
Officers have carried out three arrest warrants at addresses in the Hertfordshire area and other warrants have been executed in Milton Keynes.
Detective Inspector Lee McCullough said: “My team is acting on a number of leads to bring in those wanted for questioning in relation to this awful incident.
“I am continuing to appeal to Arthur Collins and the two men who were seen with him to hand themselves in so that we can talk to them about the incident in the nightclub. I would also urge anyone who knows of his whereabouts to contact police.
“Equally, anyone found harboring those wanted for questioning by police can expect a knock at the door and could well find themselves under arrest.
“We have 20 people suffering from the effects of an acidic substance being sprayed in a confined space in a busy nightclub. All have burn-related injuries. This incident has caused suffering to a large group of people and left a young man and a woman women blinded in one eye and many others needing long term treatment.
“The noxious substance used has not yet been confirmed but samples retrieved from the scene have been sent for analysis. If you were there and saw anyone involved inside or leaving the nightclub, please get in touch.”
Anyone with information that may assist police should call detectives from Hackney CID via 101 or via Twitter @MetCC. To remain anonymous, call Crimestoppers on 0800 555 111.
A 33-year-old woman was arrested at one of the addresses on Thursday, 20 April on suspicion of firearms offences. She was taken to a north London police station and has since been bailed to a date to be confirmed.
Detectives are continuing to appeal for information to trace a man wanted for questioning in connection with the incident.
Arthur Collins, 25, of Hertfordshire is wanted for questioning by police. Anyone with information on his whereabouts is urged to make contact with investigators. He should not be approached by members of the public. If seen the public are advised to call 999 immediately.
Two other men are also wanted for questioning in connection with this incident. CCTV images of the two further males are currently being reviewed by investigators.
Officers were called to the nightclub on Sidworth Street in Dalston, at approximately 01:10hrs on Monday, 17 April, after members of the public complained of a noxious substance.
The London Fire Brigade and London Ambulance Service also attended.
Two men aged 24 (Victim 1) and 29 (Victim 2) have been transferred to a specialist burns hospital in Essex where they remain in a serious but stable condition.
A total of 12 people attended hospital suffering burns. Ten people were taken by ambulance and two people presented themselves at an east London hospital.
The others were treated for various injuries.
As a result of the incident a total of 20 people have now been identified as suffering various burns.
Officers have since been informed that a 22-year-old woman who suffered burns to her face has been blinded in her left eye.
Officers believe a dispute between two groups of people developed inside the venue, resulting in a noxious substance being sprayed by a male suspect directly at Victims 1 and 2. Other people inside the venue suffered the effects of the substance.
The substance is yet to be identified, but it is believed to have been acidic.
There have been no arrests in connection with the incident in the club and enquiries continue. There is nothing to suggest that this is gang-related.