Australian airline Qantas has grounded its fleet of Airbus A380s after an engine failure forced a passenger plane to make an emergency landing in Singapore.

Flight QF32, which originated in London, was travelling from Singapore to Sydney with 433 passengers and 26 crew on board.

The Airbus A380 superjumbo experienced "a significant engine failure" less than 15 minutes after take-off.

Metal debris - including a piece carrying the airline's famous "flying kangaroo" logo - was recovered by locals on the Indonesian island of Batam.

The Qantas pilot dumped the jet's fuel and returned safely to Singapore's Changi airport. No-one was hurt in the incident.

Inspections of the damaged engine have begun, but the problem has been identified as an "uncontained engine failure".

Former BA pilot Alastair Rosenschein told Sky News: "It looks initially like it's a turbine blade or a fan blade failure, which has then done further damage to the engine.

"What is of particular concern for any pilot is that the failure was uncontained.

"That means it actually broke free of the casing of the engine and therefore may have done additional damage to the aircraft.

"If there had been damage to the cabin, that would cause depressurisation.

"Any form of uncontained failure with an engine as big as this - and this is the largest airline engine in the world - the damage could be quite substantial."

Qantas announced it was grounding all six of its A380 airbuses - the flagship of its 191-strong fleet.

Chief executive Alan Joyce told reporters: "This... engine failure has been one that we haven't seen before.

"So we're obviously taking this very seriously."

A spokesman for Airbus said the company was offering technical assistance with the official investigation.

Rolls-Royce is also helping with the probe, as it produced the Qantas engines.

"The investigation is at an early stage. We are aware of the situation and are working with our client," a spokesman said.

Passenger Ulf Waschbusch told Sky News he was sitting over the wing when he heard "a boom sound".

"I saw a few flares coming out from where the engine was located and saw immediately there were problems," he said.

Another passenger, Rosemary Hegardy, said she heard two bangs and also saw flames from her window.

"There were flames - yellow flames came out, and debris came off," the 60-year-old said.

"You could see black things shooting through the smoke, like bits of debris."

The Airbus superjumbo has been in service since Singapore Airlines took delivery of the first of the A380 planes in late 2007.

The double-decker A380 is the largest passenger plane in the world.

Emirates, the biggest single-customer of Airbus A380, said it had no plans to ground its 13 superjumbos.

Lufthansa also said it would not ground its A380 jets, but it is understood the airline does use Rolls-Royce engines.

However, Singapore Airlines - which also uses Rolls-Royce - indictated it would delay all its A380 flights pending "precautionary technical checks".

Qantas' safety record is exemplary among major airlines, with no jet fatalities in its 90-year history.

The company's last deadly crash happened in 1951 when a small Qantas plane plunged into the sea off Papua New Guinea, killing seven people.