An additional two individuals are now in custody in connection with a theft at London's Heathrow Airport in which 21 people were injured by what is thought to be pepper spray, according to police.
A 24-year-old man, was taken into custody in the Lambeth area for suspected theft and assault and a woman, 23 was detained for suspected conspiring to commit a robbery. They both are still being held, the force said.
The arrests come after an investigation into an attack at the multi-storey car park at Terminal 3 this past Sunday. Before the attack, a pair of female travelers were robbed of their suitcases upon exiting a car park lift.
A three-year-old girl was one of the injured during the incident. A total of five individuals went to hospital for medical care and have since been discharged.
Police arrested a 31-year-old man on suspicion of theft and assault close to the scene. He has since been released pending further inquiries as the investigation proceeds.
Police were alerted at approximately 8:10 in the morning GMT following reports of several people injured by an irritating chemical believed to be pepper spray.
The attack - an event that police said was isolated and not considered an act of terror - caused train delays and the partial closure of the main airport tunnel and the Terminal 3 parking facility for a short time.
