A man has been arrested on suspicion of assault after number of people were attacked with “a form of pepper spray” by a group of men at a car park at Heathrow Airport, police said.Officers were called at 8.11am on Sunday to reports multiple people had been assaulted at the multi-storey car park at Terminal 3.Armed police attended and found a number of people who had been sprayed with what the Metropolitan Police said is believed to be a form of pepper spray by a group of men who then fled the scene.