London: Investigators were on Saturday searching for the cause of the fire onboard a 787 Dreamliner parked at London's Heathrow airport, which raises further questions about the safety of Boeing's next-generation jet.
A team from Britain's Air Accident Investigation Board (AAIB) was deployed following the blaze on Friday afternoon on the Ethiopian Airlines plane, which was fortunately empty at the time.
"The aircraft was moved to a secure hangar early this morning. The investigation is ongoing," a spokesman for the AAIB, an agency of the Department of Transport, told AFP.
Television pictures showed burn marks on the top of the plane near the back, just in front of the vertical stabiliser.
The US Federal Aviation Administration (FAA) said it had also sent an official to support the work of the US National Transportation Safety Board (NTSB) in Britain.
A spokesman for Ethiopian Airlines said it was investigating the incident but had no plans to ground its fleet of four 787 Dreamliners.
"Ethiopia's Dreamliners will continue to fly," Hailu Teklehaimanot told AFP in Addis Ababa.
"The incident at Heathrow is not being treated as flight related as the incident happened after being grounded for eight hours."
The fire is a blow for Boeing, which had to temporarily withdraw the Dreamliner from service earlier this year after concerns that batteries on board could cause fires.
The US aviation giant has since rolled out modifications it said would ensure the planes were safe.
Boeing's shares closed 4.7 percent lower at $101.87 in New York trading on Friday, clawing back from a dive of more than seven percent.
Heathrow shut down for 90 minutes after the incident, and the world's busiest international passenger air hub was still reporting knock-on delays on Saturday.
"The airport is fully operational but with some flight delays and cancellations," Heathrow said in a statement.
A spokeswoman told AFP that about 40 flights had been cancelled throughout the day, largely due to aircraft being out of place, but said delays to other flights were "minimal".
In a separate incident on Friday, another Dreamliner flying from Manchester to Florida was forced to turn back after experiencing a "technical issue" after take-off.
It was operated by Thomson Airways, which had only three days earlier become the first British airline to fly the plane.
The airline stressed the diversion was a "precautionary measures", adding: "Passengers have disembarked and our dedicated team of engineers are now inspecting the aircraft."
A global grounding order on the Dreamliner was issued in January after lithium-ion batteries overheated on two different jets, with one of them catching fire while the aircraft was parked.
Boeing has not been able to identify the root cause of the problems -- a source of major embarrassment to the company -- but said its modifications would prevent the problems reoccurring.
In April, an Ethiopian Airlines Dreamliner -- reported to be the same plane that caught fire at Heathrow -- flew from Addis Ababa to Nairobi on the first commercial flight since the grounding.
But the planes have been dogged by problems, with a string of flights worldwide cancelled or diverted due to mechanical issues.