An additional two individuals are now in custody in connection with a robbery at London's Heathrow Airport in which 21 people were injured by a substance believed to be pepper spray, according to police.
A man, 24, was arrested in Lambeth for suspected robbery and assault and a woman, 23 was arrested on suspicion of conspiracy to commit robbery. They both remain in custody, authorities confirmed.
The arrests follow an investigation into an attack at the multi-level parking garage at Terminal 3 this past Sunday. Prior to the incident, two women had stolen from them their luggage upon exiting a car park lift.
A three-year-old girl was one of the injured in the event. A total of five individuals were taken to the hospital for treatment and were later released.
Police detained a 31-year-old man for suspected theft and assault close to the location. He has since been released under investigation while inquiries continue.
Police were alerted at about 8:10 in the morning GMT following reports of several people hurt by an irritating chemical believed to be pepper spray.
The attack - an event that police said was isolated and not being treated as terrorism - caused delays to rail services and the partial closure of the Central Terminal Area tunnel and the T3 parking facility briefly.
