An additional two individuals are now in custody related to a theft at London's Heathrow Airport in which 21 people were injured by what is thought to be an irritant spray, as stated by police.
A 24-year-old man, was taken into custody in the Lambeth area for suspected theft and assault and a 23-year-old woman was arrested for suspected conspiring to commit a robbery. Both individuals remain in custody, the force said.
The arrests come after a probe into an attack at the multi-storey car park at Terminal 3 on Sunday. Before the incident, two women were robbed of their luggage after getting out of a car park lift.
A toddler aged three was one of the those hurt in the event. Five people went to hospital for treatment and were later released.
Officers detained a 31-year-old man on suspicion of robbery and assault close to the location. He was subsequently released pending further inquiries while inquiries continue.
Police were called at about 08:10 GMT following reports of several individuals hurt by an irritating chemical thought to be an irritant spray.
The attack - which authorities stated was isolated and not being treated as an act of terror - resulted in train delays and the temporary shutdown of the main airport tunnel and the T3 parking facility for a short time.
