Two clubbers who were sprayed with acid in an east London nightclub were so badly injured "they couldn't see", a witness has said.
The two men were among 16 who suffered burns during the attack at the Mangle E8 venue in Sidworth Street, Hackney, at about 01:10 BST on Monday.
A 20-year-old woman, who was also injured, said the men were "two black guys, but their faces were turned white because of the acid".
No-one has been arrested.
The injured men, aged 29 and 24, are in a serious but stable condition in a specialist burns unit in Essex.
The witness, who asked not to be named, said she had not see any argument or fight in the club but "in the space of two minutes people went from dancing to the acid being thrown".
"I was standing by the bar and then I got hit by something that at first felt like water but then my arms started blistering," she said.
A 25-year-old woman who suffered burns to her foot said people in the "packed" venue suddenly started shouting "go, go, go" and "let's move, let's move".
She said the acid had caused a "red circle" around her toes around the size of a 50p piece, which caused a strong "stinging" pain.
"It is scary because you just go out to have a good night and you realise how close it could have been to being a lot worse," she said.
Two Australian sisters who were also injured told the BBC they thought someone had "bombed the club" after they smelt gas.
Former Premier League footballer Jamie O'Hara said his cousin, who was in the club, had suffered blisters all over her head.
"Innocent people get injured for the sick act of violence," he tweeted.
Three cast members of the reality TV show The Only Way Is Essex - Jamie Reed, Jade Lewis and Chloe Meadows - were also reportedly among the hundreds evacuated from the LoveJuice event.
A London Fire Brigade spokeswoman said an "unknown corrosive substance" had been thrown.
"It was identified by a pH paper test as a strong acidic substance," she said.
Some witnesses have criticised security saying sufficient searches had not been carried out at the event but the club's owners have not commented.
The company behind the event tweeted it was co-operating with the police investigation.