Two more people are now in custody related to a robbery at Heathrow Airport in which 21 people were injured by what is thought to be pepper spray, according to police.
A man, 24, was arrested in Lambeth on suspicion of theft and assault and a woman, 23 was arrested on suspicion of conspiring to commit a robbery. They both remain in custody, the force said.
The arrests come after a probe into an assault at the multi-storey car park at Terminal 3 on Sunday. Before the incident, a pair of female travelers were robbed of their luggage after getting out of a car park lift.
A toddler aged three was one of the injured during the incident. Five people were taken to the hospital for medical care and have since been released.
Police detained a 31-year-old man on suspicion of robbery and assault near the scene. He has since been released under investigation as the investigation proceeds.
Police were alerted at approximately 8:10 in the morning GMT after reports came in regarding several individuals hurt by an irritating chemical believed to be an irritant spray.
The attack - which police said was isolated and not being treated as an act of terror - caused delays to rail services and the temporary shutdown of the Central Terminal Area tunnel and the Terminal 3 car park briefly.
