An additional two individuals are now in custody related to a theft at London's Heathrow Airport where 21 people sustained injuries by what is thought to be an irritant spray, according to police.
A 24-year-old man, was arrested in the Lambeth area on suspicion of robbery and assault and a 23-year-old woman was detained on suspicion of conspiring to commit a robbery. Both individuals remain in custody, the force said.
The arrests follow an investigation into an attack at the multi-storey car park at Heathrow's Terminal 3 on Sunday. Prior to the incident, a pair of female travelers were robbed of their suitcases after getting out of a car park lift.
A three-year-old girl was one of the injured in the event. Five people went to hospital for medical care and were later discharged.
Officers arrested a 31-year-old man on suspicion of theft and assault near the location. He has since been released under investigation while inquiries continue.
Police were called at about 08:10 GMT following reports of several individuals injured by an irritating chemical thought to be an irritant spray.
The attack - which police said was isolated and not considered an act of terror - caused delays to rail services and the temporary shutdown of the main airport tunnel and the T3 parking facility briefly.
