An additional two individuals are now in custody related to a robbery at Heathrow Airport where 21 people were injured by what is thought to be pepper spray, according to law enforcement.
A man, 24, was arrested in Lambeth for suspected theft and assault and a woman, 23 was detained on suspicion of conspiring to commit a robbery. Both individuals are still being held, authorities confirmed.
The arrests come after an investigation into an assault at the multi-storey car park at Heathrow's Terminal 3 this past Sunday. Before the incident, two women had stolen from them their luggage upon exiting a car park lift.
A three-year-old girl was among the injured during the incident. A total of five individuals went to hospital for medical care and were later released.
Officers detained a 31-year-old man for suspected robbery and assault near the scene. He has since been released under investigation while inquiries continue.
Authorities were called at approximately 8:10 in the morning GMT following reports of several people hurt by an irritating chemical thought to be an irritant spray.
The attack - which authorities stated was isolated and not considered 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 briefly.