Two Arrests Following London Heathrow Irritant Spray Attack

An additional two individuals are now in custody related to a theft at London's Heathrow Airport in which 21 people were injured by a substance believed to be pepper spray, according to law enforcement.

A man, 24, was arrested in the Lambeth area on suspicion of robbery and assault and a 23-year-old woman was arrested on suspicion of conspiracy to commit robbery. They both remain in custody, authorities confirmed.

These detentions follow an investigation into an assault 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 upon exiting a parking garage elevator.

A toddler aged three was one of the injured in the event. Five people went to hospital for treatment and have since been discharged.

Police arrested a man in his thirties on suspicion of theft and assault near the location. He was subsequently released under investigation while inquiries continue.

Police were called at about 8:10 in the morning GMT following reports of a number of individuals injured by an irritating chemical believed to be pepper spray.

The assault - which authorities stated was isolated and not considered terrorism - caused delays to rail services and the temporary shutdown of the main airport tunnel and the Terminal 3 car park briefly.