Two Indonesian women from an area just east of the capital are in hospital after local tests showed they had the H5N1 bird flu virus, a senior Health Ministry official said on Thursday.

Hariadi Wibisono, director of control of animal-borne diseases at the ministry, said the two women -- one aged 27 and the other 22 -- were being treated at a Jakarta hospital designated for bird flu patients.

"We received the results last night. Their health condition now is worsening," Wibisono said.

Further blood samples had been sent to a Hong Kong laboratory recognised by the World Health Organisation for confirmation.

Indonesia has had 16 WHO-confirmed deaths from bird flu and seven confirmed cases where patients have survived.

The two women are not related, but hail from the same suburban Jakarta area of Bekasi.

Sulianti Saroso hospital spokesman Ilham Patu said it was not clear how they may have picked up the virus. At least one had no direct contact with chickens, he said.

Most Indonesian cases have shown the victims had contact with dead chickens.

Turkey, Iraq and Nigeria have in recent weeks become the latest countries outside Asia to report human cases of the H5N1 strain of avian flu.

While it mostly affects birds, the virus has killed at least 88 people in seven countries since 2003, according to the World Health Organisation.

Experts fear the H5N1 virus will mutate to become easily passed between humans, triggering a pandemic. The current H5N1 strain of bird flu has not mutated.

The highly pathogenic strain of bird flu has affected birds in two-thirds of the provinces in Indonesia, an archipelago of about 17,000 islands and 220 million people.

The country has millions of chickens and ducks, many in the yards of rural or urban homes, making it likely that more humans will become infected with the virus.