An individual has been detained by police at London’s Heathrow Airport following an incident where pepper spray was used on a crowd during a robbery at a parking garage, leading to significant travel delays.

Authorities reported that five people were transported to a hospital, while an additional 16, including a three-year-old child, received on-site medical attention. Fortunately, none of the injuries appeared to be severe.

The chaotic scene unfolded in the Terminal 3 parking garage when four men reportedly stole a woman’s suitcase inside an elevator and sprayed her with a chemical irritant, according to the Metropolitan Police.

Eyewitness Tom Bate recounted seeing three young men dressed in black, with their faces obscured, fleeing from the elevator. He described a sudden burning sensation in his throat, followed by intense coughing.

“Everyone in the vicinity started coughing,” he shared with Sky News.

“It was one of the most bizarre experiences I’ve ever encountered.”

Police said the robbery victim and the assailants knew each other and the crime was not being investigated as terrorism.

Bate said he initially feared the worst as a large group of officers carrying guns – a rarity in the UK where most police don’t carry weapons – ran past him shouting.

“It was absolutely terrifying and I 100 per cent believed that I was in a terrorist attack for a few moments,” he said.

He said an officer pointed a gun at a man and ordered him to the ground to arrest him.

A 31-year-old man was held on suspicion of assault. Police were searching for the other suspects who left the scene.

The incident caused several hours of delays for passengers trying to get to and from the airport.