By: ELLIE FLYNN

PASSENGERS were forced to evacuate an American Airlines plane using the emergency slides at Heathrow after a technical issue caused smoke to fill the cabin. The airbus A330 with 277 passengers on board was evacuated on the terminal 3 runway due to smoke in the cabin at around 12.30pm today. Fire crews remain at the scene after passengers were evacuated due to smoke in the cabin Most passengers and crew got off the plane using the jet bridge. About 12 passengers used the emergency slides to get off the plane a few minutes after boarding. Video uploaded on Twitter showed the passengers coming down the inflated slides and onto the runway. Fire engines were seen surrounding the plane as flyers made their way off. Ross Hiscock, 28, was on a flight that landed at Heathrow from Helsinki when he saw smoke coming off the tail-end of the plane next to his. He said: “I saw a lot of smoke come out from the tail-end of the aircraft. I wondered if it was normal, whether it was just exhaust fumes. “Then the door opened on the right side of the aircraft and crews deployed slides from the rear and the middle of the plane. “Next we wondered whether it was a drill, but then we saw they were real passengers. I saw at least one carrying a child. “It all happened in a matter of seconds. Everyone seemed to be okay.” Another eyewitness said around 10 fire engines, seven ambulances and a number of police were at the scene. He told the Mirror Online: “From what I heard there was smoke coming off the back engine of the plane and it set off smoke detectors which caused the emergency slide to be deployed.” A number of passengers and crew are being treated by medical personnel.