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 an irritant spray, as stated by police.
A man, 24, was arrested in the Lambeth area for suspected theft and assault and a woman, 23 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 on Sunday. Before the attack, a pair of female travelers had stolen from them their suitcases after getting out of a parking garage elevator.
A toddler aged three was one of the those hurt in the event. Five people went to hospital for treatment and have since been released.
Police detained a man in his thirties for suspected robbery and assault near the location. He was subsequently released under investigation while inquiries continue.
Authorities were alerted at approximately 8:10 in the morning GMT following reports of a number of people injured by an irritating chemical believed to be pepper spray.
The assault - which authorities stated was isolated and not being treated as terrorism - caused delays to rail services and the temporary shutdown of the Central Terminal Area tunnel and the T3 parking facility briefly.
