A relative of a victim of the Garuda Indonesia airliner inferno is carried away from the hospital morgue in Yogyakarta. [Photo: AFP]

The pilots of an Indonesian airliner that burst into flames after a hard landing reportedly blamed a huge gust of wind while police said Thursday they suspected human error.

The Garuda Indonesia plane dropped suddenly and landed at excessive speed at Yogyakarta airport on Wednesday, witnesses said. It careered off the runway into a rice paddy and caught fire, killing 21 people.

More than 100 passengers and crew survived the blaze, many with harrowing tales of how they scrambled for their lives before the Boeing 737 erupted.

Australian Federal Police commissioner Mick Keelty, whose forensic officers are helping to identify the dead, said the pilot and co-pilot have been interviewed by Indonesian authorities.

"They say that there was some interference with the landing and that was a natural interference caused by a huge gust of wind that took the plane off track as it came into landing," he told Australia's Channel Nine television.

Five of 10 Australians on board are feared dead, and Canberra has sent experts to help treat survivors as well as identify the dead.

Indonesia's chief national police spokesman said that early investigation pointed to human error as the cause.

"The initial investigation results indicate that the accident was caused by human error," Inspector General Sisno Adiwinoto told reporters in Jakarta.

"However, the national police continue to investigate to know whether there are elements of criminality in that accident."

Investigators recovered the airplane's black box containing a cockpit voice recorder and a data log, and sent it to Australia for analysis.

"Australia offered to do it for free -- it will be faster, so why not?" said Tatang Karnadi, Indonesia's transport safety committee chairman.

Alan Stray, an Australian transportation investigator assisting in the probe, said initial findings could be available within a few days.

Meanwhile the head of Garuda's Australian operations, Kerry Timms, defended the airline's safety record.

"I have total confidence in flying with Garuda Indonesia," Timms told Australian radio. He added the carrier had made "significant progress" in improving its safety record over the past 10 years.

Timms said it was pointless to speculate on the cause.

"There's no hard evidence yet," he said.

Transport Minister Hatta Rajasa has said the probe would be spearheaded by the Indonesian National Transportation Safety Committee (KNKT).

Australian Foreign Minister Alexander Downer said Wednesday that an Australian air force officer who survived the accident told him the plane had been going too fast when it landed.

Among the emergency response team which Australia sent to Yogyakarta was Fiona Wood, a renowned Perth-based burns specialist who helped treat survivors of the Bali bombings.

Australian and Indonesian police worked together after bombings killed more than 90 Australians on Bali in 2002 and 2005.

Families of those killed in the Garuda inferno will each receive about 65,000 dollars in financial assistance from the airline, its spokesman said.

The disaster has again called into question the blighted transport safety record in Indonesia, a vast archipelago of 220 million people.

A Boeing 737-400 owned by low-fare carrier Adam Air with 102 people aboard crashed into the sea off the island of Sulawesi on New Year's Day, leaving no survivors.

"There is a long list of disasters in the air, at sea and on land, a large number of which are the result of negligence and an attitude of ignoring safety procedures and prevention," the Koran Tempo said in an editorial.

It was difficult to prevent people from concluding that there was no safety culture in the country, it added.

"We are improving the safety aspects," transport minister Rajasa responded. He said Indonesia is experiencing the world's second-fastest passenger growth after China.