An additional two individuals are now in custody in connection with a theft at Heathrow Airport where 21 people sustained injuries by a substance believed to be an irritant spray, according to police.
A man, 24, was taken into custody in Lambeth for suspected theft and assault and a woman, 23 was arrested for suspected conspiracy to commit robbery. Both individuals are still being held, authorities confirmed.
These detentions come after a probe into an attack at the multi-level parking garage at Heathrow's Terminal 3 on Sunday. Before the incident, two women were robbed of their suitcases upon exiting a parking garage elevator.
A three-year-old girl was one of the those hurt in the event. A total of five individuals were taken to the hospital for treatment and were later released.
Police arrested a man in his thirties for suspected robbery and assault close to the scene. He was subsequently released under investigation as the investigation proceeds.
Authorities were alerted at approximately 8:10 in the morning GMT following reports of several people hurt by an irritating chemical believed to be an irritant spray.
The assault - which authorities stated was a standalone incident and not considered an act of terror - resulted in delays to rail services and the temporary shutdown of the main airport tunnel and the T3 parking facility for a short time.
