Two more people are now in custody in connection with a robbery at London's Heathrow Airport in which 21 people were injured by a substance believed to be an irritant spray, according to police.
A 24-year-old man, was arrested in Lambeth on suspicion of theft and assault and a 23-year-old woman was arrested on suspicion of conspiring to commit a robbery. They both remain in custody, authorities confirmed.
The arrests follow a probe into an assault at the multi-level parking garage at Terminal 3 on Sunday. Before the attack, two women had stolen from them their suitcases upon exiting a parking garage elevator.
A three-year-old girl was among the those hurt during the incident. Five people were taken to the hospital for medical care and were later discharged.
Police detained a man in his thirties on suspicion of theft and assault near the scene. He was subsequently released pending further inquiries as the investigation proceeds.
Authorities were alerted at about 8:10 in the morning GMT after reports came in regarding several people hurt by a noxious substance thought to be pepper spray.
The assault - which authorities stated was isolated and not considered an act of terror - caused train delays and the partial closure of the Central Terminal Area tunnel and the Terminal 3 parking facility for a short time.
