Two more people are now in custody in connection with a robbery at Heathrow Airport in which 21 people sustained injuries by what is thought to be an irritant spray, according to police.
A 24-year-old man, was taken into custody in Lambeth on suspicion of robbery and assault and a woman, 23 was detained for suspected conspiring to commit a robbery. Both individuals are still being held, the force said.
The arrests follow a probe into an assault at the multi-level parking garage at Terminal 3 this past Sunday. Before the incident, two women were robbed of their luggage upon exiting a parking garage elevator.
A toddler aged three was one of the injured during the incident. Five people were taken to the hospital for treatment and have since been released.
Officers arrested a man in his thirties on suspicion of theft and assault close to the scene. He was subsequently released under investigation as the investigation proceeds.
Authorities were alerted at about 8:10 in the morning GMT following reports of several people hurt by an irritating chemical thought to be an irritant spray.
The assault - which police said was isolated and not considered terrorism - caused delays to rail services and the temporary shutdown of the main airport tunnel and the T3 car park briefly.