Two more people 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 an irritant spray, according to police.
A 24-year-old man, was taken into custody in Lambeth for suspected robbery and assault and a woman, 23 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-level parking garage at Heathrow's Terminal 3 this past Sunday. Prior to the attack, a pair of female travelers had stolen from them their suitcases upon exiting a car park lift.
A three-year-old girl was among the injured in the event. A total of five individuals went to hospital for treatment and have since been released.
Officers detained a man in his thirties for suspected robbery and assault near the scene. He has since been released under investigation while inquiries continue.
Police were alerted at approximately 8:10 in the morning GMT after reports came in regarding several individuals hurt by a noxious substance believed to be an irritant spray.
The attack - an event that authorities stated was a standalone incident and not being treated as an act of terror - resulted in train delays and the partial closure of the Central Terminal Area tunnel and the Terminal 3 car park briefly.
