A British Airways flight was evacuated at Heathrow after four people were taken ill from reported “fumes” on Sunday.
Emergency services rushed to respond to the incident which occurred on a flight from Barcelona at 4.15pm.
Footage of the incident showed a number of fire engines and police cars on the runway at Terminal 5 as passengers waited outside the plane.
One affected passenger said on social media: “Nothing like being locked on a plane with a ‘potential contagion’ for an hour and half with no explanation or information.
He later added: “For clarity there was no contagion in the end. At least I hope not since they finally let us go.
“The Met seems to be on the ball. Heathrow staff, though, were increasingly unclear and hostile to what amounted to very confused terrified folks that just wanted to go home.”
Another sharing images of the incident online said there was a “major police operation” at Terminal 5, while a third said: “Scenes at Heathrow T5 as the BA flight from Barcelona has had its crew fall sick upon landing, and the passengers are being held on the runway.”
The London Fire Brigade said that no elevated chemical readings were found inside the aircraft, while the Met Police said four people were treated at the scene.
A Met spokesperson said: “Police were called at 16:15hrs on Sunday, 8 October to reports of passengers taken unwell on a flight into Heathrow Airport. Emergency services attended. Four people were treated at the scene.”
A London Ambulance Service spokesperson said: “We sent a number of resources to the scene, including three medics in fast-response cars, two advanced paramedic practitioners, two ambulance crews, two incident response officers and members of our hazardous area response team (HART).
“After assessing multiple people at the scene, we treated three patients and discharged them.”
A British Airways spokesperson said: “The safety of our customers and crew is always our top priority.
“This aircraft landed normally at Heathrow following reports of a technical issue.
“Customers disembarked the aircraft safely via steps, and we’ve apologised to them for the delay and inconvenience caused to their journey.”