Two more people 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 law enforcement.
A 24-year-old man, was arrested in the Lambeth area for suspected robbery and assault and a 23-year-old woman was arrested for suspected conspiracy to commit robbery. They both 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. Before the attack, a pair of female travelers were robbed of their luggage upon exiting a car park lift.
A three-year-old girl was one of the those hurt during the incident. A total of five individuals were taken to the hospital for medical care and were later discharged.
Police arrested a man in his thirties on suspicion of theft and assault close to the location. He was subsequently released under investigation while inquiries continue.
Police were called at about 08:10 GMT following reports of a number of people injured by an irritating chemical believed to be pepper spray.
The assault - which police said was isolated and not considered an act of terror - caused delays to rail services and the partial closure of the Central Terminal Area tunnel and the T3 car park briefly.
