One person's been arrested after a string of pepper spray attacks at London's Heathrow Airport.
Twenty-one people suffered injuries, with five needing hospital treatment, after an argument escalated in a terminal carpark.
Social media footage shows a large armed police response, as the area was temporarily locked down.
UK correspondent Gavin Grey told Andrew Dickens police were quick to say it wasn't related to terrorism or a protest.
He says the people seemed to know each other, and got into an argument, which led to someone spraying a substance at people they didn't like.

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