Two more people are now in custody in connection with a theft at Heathrow Airport in which 21 people sustained injuries by a substance believed to be pepper spray, according to law enforcement.
A man, 24, was taken into custody in the Lambeth area on suspicion of theft and assault and a 23-year-old woman was arrested on suspicion of conspiring to commit a robbery. Both individuals remain in custody, authorities confirmed.
These detentions come after a probe into an attack at the multi-level parking garage at Heathrow's Terminal 3 this past Sunday. Prior to the incident, two women had stolen from them their luggage after getting out of a parking garage elevator.
A three-year-old girl was among the those hurt during the incident. Five people went to hospital for medical care and were later released.
Police arrested a 31-year-old man for suspected robbery and assault near the location. He has since been released under investigation while inquiries continue.
Police were called at about 08:10 GMT following reports of several people hurt by a noxious substance believed to be pepper spray.
The attack - which authorities stated was isolated and not considered terrorism - caused delays to rail services and the partial closure of the main airport tunnel and the Terminal 3 car park briefly.
