An additional two individuals are now in custody related to a theft at Heathrow Airport in which 21 people sustained injuries by what is thought to be an irritant spray, according to law enforcement.
A 24-year-old man, was taken into custody in the Lambeth area for suspected theft and assault and a woman, 23 was arrested on suspicion of conspiracy to commit robbery. Both individuals are still being held, authorities confirmed.
The arrests come after a probe into an attack at the multi-level parking garage at Terminal 3 on Sunday. Prior to the attack, two women were robbed of their luggage after getting out of a car park lift.
A three-year-old girl was among the injured during the incident. Five people were taken to the hospital for medical care and were later released.
Police arrested a 31-year-old man for suspected theft and assault close to the scene. He was subsequently released pending further inquiries as the investigation proceeds.
Police were called at about 08:10 GMT after reports came in regarding a number of individuals hurt by an irritating chemical thought to be an irritant spray.
The assault - which police said was a standalone incident and not being treated as an act of terror - resulted in delays to rail services and the temporary shutdown of the Central Terminal Area tunnel and the T3 car park for a short time.
