Two more people are now in custody in connection with a theft at Heathrow Airport in which 21 people were injured by what is thought to be an irritant spray, according to law enforcement.
A 24-year-old man, was arrested in the Lambeth area for suspected robbery and assault and a woman, 23 was detained on suspicion of conspiracy to commit robbery. Both individuals remain in custody, the force said.
These detentions follow an investigation into an attack at the multi-level parking garage at Heathrow's Terminal 3 on Sunday. Before the attack, two women had stolen from them their luggage after getting out of a car park lift.
A three-year-old girl was among the injured during the incident. Five people went to hospital for treatment and were later released.
Officers arrested a 31-year-old man on suspicion of robbery and assault close to the scene. He was subsequently released under investigation as the investigation proceeds.
Authorities were alerted at about 8:10 in the morning GMT after reports came in regarding several people injured by an irritating chemical believed to be pepper spray.
The attack - which police said was a standalone incident and not considered an act of terror - caused delays to rail services and the temporary shutdown of the Central Terminal Area tunnel and the T3 parking facility for a short time.
