A number of people were injured by a noxious substance in the multi-storey car park at Terminal 3 at around 8am yesterday (December 7).
21 people were treated at the scene and five were taken to hospital and have all since been discharged.
Prior to the assault, two women were allegedly robbed of their suitcases after getting out of the car park lift.
During the robbery, the men sprayed a substance, believed to be pepper spray in the direction of the women.
This substance affected those in the vicinity, causing minor injuries.
Today (December 8), officers arrested a 24-year-old man in Lambeth on suspicion of robbery and assault and a 23-year-old woman on suspicion of conspiracy to commit robbery.
They both remain in custody.
A 31-year-old man was also arrested on suspicion of robbery and assault close to the scene.
He has since been released under investigation while enquiries continue.
A spokesperson for the Metropolitan Police said: “Enquiries remain ongoing and anyone with any information is asked to contact the investigation team on 101 quoting CAD 1803 7 DEC or anonymously via Crimestoppers on 0800 555 111.”
