A NURSE says a 14-year-old girl believed to be the only survivor of a Yemeni jetliner crash is "doing well" in a hospital in Comoros.

Said Mohammed, a nurse at El Mararouf hospital in the archipelago's capital city, said doctors would release more on the girl's condition later on Wednesday.

Mohammed said he cared for the girl through the night.

The jetliner carrying 153 people crashed into the Indian Ocean on Tuesday as it attempted to land amid severe turbulence and howling winds.

Most of the passengers were from Comoros, a former French colony.

Sergeant Said Abdilai told Europe 1 radio that he rescued the girl after she was found bobbing in the water.

She couldn't grasp the life ring rescuers threw to her, so Abdilai said he jumped into the sea.

The Red Cross has warned hopes of finding more survivors were slim.

However, a black box flight recorder from the jet has been located, a French government spokesman says.

Efforts to retrieve it will begin on Wednesday, the spokesman added.

Meanwhile, Yemen's national carrier insisted it had a strict policy to ensure fleet maintenance after being criticised over its safety record following the crash.

Yemenia said in a statement it "implements a strict policy to ensure its aircraft are fully operational, with regular maintenance in line with international standards".

French Transport Minister Dominique Bussereau said on Tuesday that French inspectors had in 2007 found numerous faults on the plane, an Airbus A310-300, and that the airline was being closely monitored by EU authorities.

"The plane had not since then reappeared in our country," he said.