A 22-year-old woman who was caught up in a nightclub acid attack has been left blind in one eye, police said.
A total of 20 people were hurt following the attack, after a corrosive liquid was sprayed during an argument at Mangle in Dalston, east London, in the early hours of Monday.
It came as police investigating the attack carried out three arrest warrants at addresses in Hertfordshire.
But they are continuing to search for Arthur Collins, the 25-year-old boyfriend of reality television personality Ferne McCann, who issued a public plea for him to turn himself in.
Detective Inspector Lee McCullough said: "I am continuing to appeal to Arthur Collins to hand himself in so that we can talk to him about the incident in the nightclub.
"I would also urge anyone who knows of his whereabouts to contact police.
"We now 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.
"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."
A statement from the Metropolitan Police said two of the victims, aged 24 and 29, 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 - including a 22-year-old woman who suffered injuries to her face and has been left blinded in her left eye.
Officers believe a dispute between two groups of people developed inside the venue, resulting in a noxious substance - which police believe is acidic - being sprayed by a male suspect directly at two victims.
Other people inside the venue suffered the effects of the substance.
Police also confirmed a 33-year-old woman was arrested on suspicion of firearms offences following the raids.
It was one of three similar incidents reported by police in the capital during the last week.
Two people were injured when they were attacked with a noxious substance as they chatted in Fulham Palace Road in Fulham, south-west London, at lunchtime on Wednesday.
The Met said one of the victims, an 18-year-old man, suffered possibly life-changing injuries to his face, neck and shoulder when the suspect threw a corrosive substance over him.
A 47-year-old woman was also splashed with the mystery chemical, and was treated for burns to her neck and shoulder.
On Good Friday, a man in his 20s was sprayed with a noxious substance as he got out to investigate damage to his car in Whitethorn Street in Bow, east London.
His injuries are not thought to be permanent.
Anyone with information is asked to contact police.