Both runways at Heathrow airport have been closed after a British Airways plane had to make an emergency landing.
Heathrow said that all passengers and crew had been safely evacuated from the plane following the incident at about 9am on Friday.
There was speculation that the aircraft had run into a flock of birds.
British Airways said the plane in the emergency landing was an Airbus A319 with 75 passengers on board which returned to Heathrow shortly after take-off for Oslo due to a technical fault.
Emergency vehicles surrounded the plane and emergency chutes could be seen being deployed. London Fire Brigade said a crew from Heathrow fire station had assisted Heathrow Airport's fire service with "an aircraft fire".
"We believe the fire is now out," it added.
The plane was on Heathrow's northern runway which remained shut. Later the southern runway reopened.
TV pictures showed smoke billowing from the stricken aircraft while it was airborne.
It is believed the flight was BA762 involving an Airbus A319 aircraft. BA762 was scheduled to take off from Heathrow bound for Oslo at 7.55am.
Passengers on resumed flights at Heathrow were being warned to expect delays of 30-60 minutes as well as 30 minutes of aircraft taxiing time.