Officers were called just before 8pm on Saturday to the scene, near to the Olympic Park, to reports of multiple victims having being sprayed with acid at locations around the station and busy shopping centre.
A spokesperson for Scotland Yard was quoted by the UK Telegraph as saying: “We were called to the area around Westfield Stratford Shopping Centre to reports of a group of males spraying what is believed to be a noxious substance.
The attack focused around the 1970s shopping mall, the Stratford Centre, which is next to the bus station and a walk through to the Tube station.
Witnesses said an argument broke out among a group of people.
A man who gave his name as Hossen, 28, a Burger King assistant manager, said he saw a victim and his friend, a known local homeless man, run into the fast food outlet bathroom “to wash acid off his face”.
He said: “There were cuts around his eyes and he was trying to chuck water into them.”
“So far, we have treated at least five patients at the scene and taken three patients to hospital. We remain on scene.”
Police have arrested one man on suspicion of grievous bodily harm and are searching for others.