An additional two individuals are now in custody related to a robbery at Heathrow Airport in which 21 people were injured by a substance believed to be an irritant spray, according to police.
A man, 24, was arrested in Lambeth on suspicion of robbery and assault and a woman, 23 was detained on suspicion of conspiracy to commit robbery. They both are still being held, the force said.
These detentions follow an investigation into an assault at the multi-storey car park at Heathrow's Terminal 3 on Sunday. Prior to the incident, two women had stolen from them their suitcases after getting out of a car park lift.
A toddler aged three was one of the injured during the incident. A total of five individuals went to hospital for treatment and have since been released.
Officers detained a 31-year-old man for suspected theft and assault near the location. He was subsequently released under investigation while inquiries continue.
Authorities were alerted at about 08:10 GMT following reports of several people injured by a noxious substance thought to be pepper spray.
The attack - which police said was a standalone incident and not being treated as terrorism - resulted in delays to rail services and the partial closure of the Central Terminal Area tunnel and the Terminal 3 parking facility briefly.
