Two more people are now in custody related to 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 arrested in Lambeth on suspicion of robbery and assault and a woman, 23 was detained for suspected conspiring to commit a robbery. They both are still being held, authorities confirmed.
The arrests come after a probe into an attack at the multi-storey car park at Heathrow's Terminal 3 on Sunday. Before the incident, a pair of female travelers were robbed of their luggage after getting out of a parking garage elevator.
A three-year-old girl was one of the those hurt in the event. Five people were taken to the hospital for medical care and were later discharged.
Officers arrested a 31-year-old man for suspected robbery and assault near the location. He was subsequently released under investigation while inquiries continue.
Police were alerted at approximately 08:10 GMT after reports came in regarding a number of people hurt by an irritating chemical thought to be an irritant spray.
The assault - an event that authorities stated was isolated and not being treated as terrorism - resulted in train delays and the temporary shutdown of the Central Terminal Area tunnel and the T3 parking facility briefly.
