Singapore, Nov 6 (DPA) It was coincidence that on consecutive days Qantas passenger jets experienced engine problems that forced them to return to Singapore shortly after take-off, the Australian airline said Saturday.

Qantas spokeswoman Olivia Wirth, commenting on the latest incident, exonerated foreign maintenance facilities over the Boeing 747 that abandoned its flight Friday to Sydney after one of its engines had to be shut down.

"In fact, I can report that this recent aircraft, the 747, was actually maintained in Avalon in Australia," Wirth said. "Qantas has 85 percent of our maintenance. In fact, last year 92 percent of our maintenance was done onshore in Australia."

Qantas grounded its A380 fleet Thursday after an engine on a superjumbo failed four minutes after takeoff, raining shards of metal onto Indonesia's Batam Island below.

The A380 landed safely in Singapore, despite the second engine on the left wing failing to shut down and tyres blowing as it touched the tarmac.

The Boeing 747 with 412 passengers and 19 crew on board returned safely to Singapore's Changi airport after an engine failure.

"As a precautionary measure, the captain sought clearance to return to Singapore, and the aircraft landed safely a short time later without incident," the airline said in a statement.

Flight QF6, which returned to Changi around an hour after takeoff, had arrived from Frankfurt.