An additional two individuals are now in custody related to a robbery at Heathrow Airport in which 21 people were injured by what is thought to be an irritant spray, according to police.
A man, 24, was arrested in Lambeth on suspicion of robbery and assault and a 23-year-old woman was detained for suspected conspiracy to commit robbery. Both individuals are still being held, the force said.
The arrests come after an investigation into an attack at the multi-storey car park at Heathrow's Terminal 3 on Sunday. Prior to the attack, a pair of female travelers were robbed of their luggage after getting out of a car park lift.
A three-year-old girl was one of the those hurt in the event. Five people were taken to the hospital for treatment and have since been discharged.
Officers arrested a 31-year-old man for suspected theft and assault near the location. He was subsequently released under investigation as the investigation proceeds.
Police were alerted at about 08:10 GMT following reports of a number of individuals hurt by a noxious substance believed to be an irritant spray.
The attack - an event that police said was a standalone incident and not considered an act of terror - caused train delays and the temporary shutdown of the main airport tunnel and the Terminal 3 parking facility briefly.
