A Pair of Arrests in the Aftermath of Heathrow Irritant Spray Attack

An additional two individuals have been arrested related to a robbery at London's Heathrow Airport where 21 people sustained injuries by a substance believed to be an irritant spray, according to police.

A man, 24, was taken into custody in Lambeth on suspicion of robbery and assault and a 23-year-old woman was detained on suspicion of conspiring to commit a robbery. They both 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. Before the attack, 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 during the incident. Five people went to hospital for medical care and have since been released.

Police arrested a 31-year-old man on suspicion of theft and assault near the location. He was subsequently released under investigation while inquiries continue.

Police were alerted at approximately 8:10 in the morning GMT following reports of several people hurt by an irritating chemical believed to be pepper spray.

The assault - which police said was a standalone incident and not being treated as terrorism - caused delays to rail services and the partial closure of the main airport tunnel and the Terminal 3 parking facility for a short time.