SINGAPORE Airlines resumed flying its A380 fleet today, lifting a grounding order imposed after a Qantas A380 engine failed in flight, forcing the aircraft to make an emergency landing.

The Qantas engine failure, which forced the plane back to Singapore airport yesterday, marks the biggest incident with the A380, the world's largest passenger plane which has been in service only since 2007. Qantas' A380 fleet remains grounded.

Singapore airlines said it had checked and cleared its entire fleet of 11 Airbus A380 aircraft for service, said a spokeswoman for the airline in Australia.

All 11 of Singapore Airlines' A380 aircraft had been inspected and were found be safe, Susan Bredow told Reuters.

"They have all been inspected in accordance with the requirements of Airbus and Rolls-Royce. That was done overnight and everyone is satisfied the aircraft are serviceable and will be back on their scheduled routes as soon as possible," she said.

Australia's Qantas Airways yesterday grounded its six A380 aircraft, pending the outcome of investigations into the reasons for the failure of one of its four Rolls-Royce engines which appeared to break apart during the Sydney-bound flight.

British engine maker Rolls-Royce issued a statement urging operators of the aircraft to perform safety checks on its Trent 900 engines.

One passenger aboard flight QF32 reported hearing a "massive bang". Qantas described it as a significant engine failure.

Photographs of the engine showed its outer, rear casing had been torn apart.

Passengers also reported that a second engine on the stricken Qantas aircraft failed to shut down once on the tarmac, sparking fears it could ignite spilling fuel from the failed engine.

Passengers said they were warned of the dangers of using any electronic device, as firefighters sprayed the aircraft which was leaking fuel from a hole in the wing.

"Despite all the lights being off, everything being turned off, there was a rumbling in the plane," passenger James Henderson told Australian radio.

"And the captain then came out and said, 'Oh look we are sorry. As you can probably gather, one of our engines won't turn off but we are now pouring water into it to stop it'."

Passenger Christopher Lee said: "Obviously in the back of your mind you're concerned about a very hot engine next to leaking fuel. Obviously you're in a state of anxiety."

A Qantas spokesperson could not confirm the passengers' report of a second engine problem.