Both runways at Heathrow Airport were closed today after a fire on an Ethiopian Airlines jet.
Arrivals and departures were suspended at 1630 after smoke was spotted coming from towards the rear of the Boeing 787 aircraft.
The runways reopened shortly before 1800 but passengers have been warned to expect delays.
The Dreamliner was parked at a remote stand away from the terminal buildings and nobody was thought to have been onboard.
A Heathrow spokesman said: "We can confirm there has been an on-board internal fire involving an Ethiopian Airlines aircraft and the airport's emergency services are in attendance.
"The aircraft was parked on a remote parking stand. There were no passengers on board and there are no reported injuries at this time.
"Arrivals and departures were temporarily suspended while airport fire crews attended to this incident. This is a standard procedure if fire crews are occupied with an incident."
A police spokesman said said: "Police at Heathrow were alerted to a fire on a plane. Emergency services are in attendance.
"At this time it is believed no one was on board and there are no reports of any injuries. The fire is being treated as unexplained."
The B787 was grounded for three months in January due to a faulty battery system causing problems in two different planes operated by Japan Airlines and ANA (see online news, January 11).
Ethiopian Airlines then became the first carrier to again operate a commercial Boeing 787 flight, between Addis Ababa and Nairobi, Kenya (see online news, April 29).