An additional two individuals are now in custody related to a robbery at Heathrow Airport where 21 people were injured by a substance believed to be pepper spray, according to law enforcement.
A 24-year-old man, was taken into custody in Lambeth on suspicion of theft and assault and a 23-year-old woman was detained for suspected conspiracy to commit robbery. Both individuals remain in custody, the force said.
The arrests come after an investigation into an assault at the multi-storey car park at Heathrow's Terminal 3 this past Sunday. Prior to the attack, two women were robbed of their suitcases upon exiting a car park lift.
A three-year-old girl was among the injured in the event. Five people went to hospital for treatment and have since been discharged.
Officers arrested a man in his thirties for suspected robbery and assault close to the scene. He was subsequently released pending further inquiries as the investigation proceeds.
Authorities were alerted at approximately 8:10 in the morning GMT after reports came in regarding a number of individuals hurt by a noxious substance thought 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 briefly.
