Confirmation has come from a laboratory in Hong Kong that a 29-year-old woman who died last week at a hospital in Jakarta had bird flu, bringing total fatalities in Indonesia to 13.

The 29-year-old woman, who was transferred to the hospital last Monday from Harapan Bunda Hospital in East Jakarta, had acute pneumonia and a high fever.

It is believed the virus was passed to her from neighborhood chickens, as a number of birds in the area died suddenly shortly before she became sick, reported The Jakarta Post newspaper on Tuesday.

Tests are underway at the Hong Kong lab to determine the status of a 39-year-old man who died here last week.

Sulianti Saroso Hospital spokesman and head of avian influenza surveillance, Ilham Patu said said the 13-year-old girl who died Saturday in Indramayu, West Java, and her younger brother and older sister had all tested positive for bird flu in Health Ministry tests.

"We are still examining the cases. We have sent their blood samples to Hong Kong for confirmation," he said.

The 13-year-old girl was admitted to Indramayu Hospital last Thursday. The decision to transfer her to Sulianto Saroso came too late and she died en route to Jakarta.

Tests subsequently conducted around her neighborhood found several chickens and fowls infected with avian influenza.

Ilham said the condition of the girl's brother and sister, who are being treated at Hasan Sadikin Hospital in Bandung, had not improved.

Experts have warned that if the virus becomes more easily transmitted between birds and humans, or between humans, millions could die in a global pandemic.