Parts of Heathrow Airport were briefly locked down Sunday morning after what appeared to be pepper spray was used during a fight in one of the airport’s parking garages, the police said.
According to the Metropolitan Police, officers were called to a parking garage at Terminal 3 in Heathrow around 8 a.m. Sunday after reports of an altercation involving a sprayed substance. A group of men used what appeared to be a type of pepper spray before fleeing the area, the police said.
The London Ambulance Service treated 21 people at the scene, the organization said in a statement, and five of those patients were sent to the hospital. The police described the injuries as non-life-changing and non-life-threatening.
One man was arrested on suspicion of assault, the police said, adding that they were searching for more suspects. The episode was not being treated as terrorism, the police said.
“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,” the Metropolitan Police said in a statement.
The episode caused a brief but high-stakes security frenzy at Heathrow, one of the world’s busiest travel hubs. National Rail halted its Elizabeth Line service to the airport for more than an hour during the police response, and a main highway into the airport was briefly closed.
The incident was contained by late Sunday morning, airport officials said in a statement, but traffic remained congested around the complex, and travelers were encouraged to take public transport. An increased police presence would remain, airport officials said, “to maintain the safety of people in the area and reassure the public.”
Police officers were still blocking roads around the airport about three hours after the initial response, according to the BBC.
The airport has been disrupted multiple times in the past year. In March, a fire at a London substation cut off power to the hub and sent a ripple of travel disruptions across the world. In July, a radar issue disrupted flights across Britain, including out of Heathrow.