An additional two individuals are now in custody in connection with a theft at Heathrow Airport in which 21 people were injured by what is thought to be pepper spray, according to police.
A man, 24, was taken into custody in Lambeth on suspicion of theft and assault and a woman, 23 was arrested on suspicion of conspiracy to commit robbery. Both individuals are still being held, the force said.
These detentions come after a probe into an attack at the multi-level parking garage at Heathrow's Terminal 3 on Sunday. Prior to the attack, a pair of female travelers had stolen from them their luggage upon exiting a parking garage elevator.
A three-year-old girl was one of the injured during the incident. A total of five individuals were taken to the hospital for treatment and have since been discharged.
Police arrested a man in his thirties on suspicion of robbery and assault close to the scene. He was subsequently released under investigation while inquiries continue.
Authorities were called at about 08:10 GMT following reports of a number of individuals injured by an irritating chemical believed to be pepper spray.
The attack - which police said was a standalone incident and not being treated as an act of terror - caused delays to rail services and the partial closure of the Central Terminal Area tunnel and the T3 car park briefly.
