Police arrested two more people they suspect were involved in a pepper spray attack at London Heathrow Airport.
A man earlier arrested was released but is still ‘under investigation.’
The incident left 21 people requiring treatment.
The Metropolitan Police said the incident was not terrorism related but was part of an attempted robbery of passengers’ luggage.
“An investigation established that, prior to the assault, two women were robbed of their suitcases after getting out of the car park lift,” the Met Police said.
“During the robbery, the men sprayed a substance believed to be pepper spray in the direction of the women. This substance affected those in the vicinity, causing minor injuries.”
A second man and a woman were arrested on Monday.
The incident took place in the Terminal 3 multi-storey car park.
London Ambulance Service said it treated 21 people, with five requiring hospital treatment.
It caused major travel disruption at the airport until it was ruled out as terrorism related.
“At this stage, we believe the incident involved a group of people known to each other, with an argument escalating and resulting in a number of people being injured,” said Commander Peter Stevens of the Met Police.
