American Airlines passengers forced to flee down emergency slide as flight is evacuated at Heathrow Airport after smoke fills cabin

Passengers have been forced to evacuate an American Airlines flight in London today due to smoke in the cabin.

The incident happened at 12.30pm at Heathrow Airport's Terminal 3, with around a dozen people having to use the emergency slides to get out of the plane. 

Emergency services have been called to the scenes as the passengers made their way to safety.

Smoke could be seen coming from the rear of the aircraft, forcing passengers to flee to safety

A video was posted on Twitter by Ross Hiscock, who was on another plane. It shows the American Airlines passengers throwing themselves down the slides at the rear of the aircraft

Pictured, a man slides down an emergency inflatable after the American Airlines plane was evacuated

A 50-second video was posted on Twitter by Ross Hiscock, 28, who was on another plane.

It shows the American Airlines passengers throwing themselves down the slides at the rear of the aircraft.

Smoke could be seen coming from the rear of the aircraft, in a picture which was taken before the evacuation. 

Reports have suggested that there was a fault in the auxiliary power unit, which is a small jet engine housed in the tail of the aircraft.