The Australian airline Qantas has grounded its six-strong fleet of Airbus A380 airliners after one of the superjumbos made an emergency landing.
Qantas flight QF32 experienced engine trouble shortly after taking off from Singapore on its way to Sydney.
One of the engines exploded with a bang, a passenger told the BBC, and debris was found on an island below.
Singapore Airlines said its A380 flights would be delayed pending technical checks.
Qantas said the plane, with 433 passengers and 26 crew on board, experienced an "engine issue" over western Indonesia shortly after taking off from Singapore at about 1000 (0200 GMT).
"It's a significant engine failure," Qantas chief executive Alan Joyce said at a news conference.
"We do take our safety reputation and our safety standards unbelievably seriously. And we're not going to take any risks with passenger safety - and as a precaution, we're suspending the flights of the A380 aircraft until we're comfortable that we understand the reasons for this."
No one was injured during the incident, which ended at Singapore's Changi airport.
Smoke billowed from the aircraft, which aviation experts say is capable of flying on two engines.
One of the engines was blackened and its rear casing was missing.
A team of air crash investigators is being sent to Singapore from France, where Airbus is based, to assist in the investigation.
A spokesman for Rolls-Royce, the British firm which made the plane's Trent 900 engines, said it would work with Qantas to identify the problem.
'Big scare' "I was on the plane right next to engine two, which exploded with a loud bang within the first 10-15 minutes of take-off," Lars Sandberg - a DJ who was travelling to Sydney to begin a music tour of Australia - told the BBC.
"I thought that something had fallen down in cargo underneath the plane, but the plane started shaking... I'm a little bit shaken up. I travel a lot and this is the first big scare I've had.
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Qantas boss Alan Joyce announced the grounding of its six A380s
"The captain did a good job, though, in reassuring us, making announcements every few minutes."
One eyewitness quoted by the AFP news agency spoke of seeing a "little bit of fire" coming from the stricken engine. Others have spoken of seeing one of the wings "broken", or with a hole in it, but this has not been confirmed.
Passengers said the pilot spent at least an hour and a half circling and discharging fuel ahead of the emergency landing.
"When we got off and saw the engine itself and the back casing burnt off, that was pretty scary," Mr Sandberg said.
"I'm just happy to be alive and safe in the terminal building."
On the Indonesian island of Batam, witnesses said they heard an explosion as the plane flew overhead, and pieces of debris were discovered.
A teacher on Batam, Indra Kurniawan, told the BBC World Service that parts of the plane hit his school.
"We were in the middle of our sport lesson outside the classroom and we heard an explosion above my head and it was loud.
"Then I saw rubbish in the sky but after one of the pieces hit our school, we all knew it was debris from the plane.
"There were three pieces - the biggest was about 15 sq cm. I touched one of the pieces and it was hot," he said.
The BBC's Nick Bryant in Sydney says aviation experts have identified the debris as part of a Qantas engine casing.
The grounding will mean inconvenience for thousands of passengers who had been scheduled to fly on the aircraft, correspondents say.
Those aboard the stricken aircraft may also have a significant wait ahead to get to their destinations as there are so many of them to re-route.
Singapore Airlines, another A380 operator, says it has been advised to carry out "precautionary technical checks" on its aircraft - powered by the same Rolls-Royce motors used on Qantas A380s.
Air France-KLM, Lufthansa and Emirates - which use engines built by a consortium called Engine Alliance - say they have no plans to ground their fleets.
Qantas had no immediate comment on whether the incident might be related to eruptions of Indonesia's Mount Merapi over the past 10 days - which have prompted some flights above the volcano to be suspended.
Bad timing
Airbus A380
- World's biggest passenger jet, with two full-length decks
- Can carry up to 800 passengers
- Can fly 15,200 km (9,424 miles)
- First commercial flight October 2007
- Length 73m (238ft)
- Wingspan 80m (262ft)
This incident is a worrying development for Qantas, an airline which prides itself on an exemplary safety record.
For the European manufacturer Airbus, the timing of this incident could hardly have come at a worse time, reports the BBC's Christian Fraser in Paris, as the Chinese President Hu Jintao is in Paris to complete negotiations for a new order of Airbus A350 and A330 passenger planes.
The closest the airliner has come to a similar incident was in September 2009, when a Singapore Airlines A380 turned around in mid-flight and returned to Paris after one of its four engines failed.
The A380, which made its maiden flight in 2007, is the flagship of the European aviation giant's fleet.
The result of a long and costly research programme, it made its first commercial flight in 2007. It is the world's largest passenger airliner, a double-decker which can carry up to 800 people - though Qantas A380s are set up to carry about 450.
I like them........
