Indonesia is investigating a possible cluster of bird flu cases after a man died and his brother and sister were hospitalised, one of them testing positive for bird flu, a doctor said yesterday.

The man, 25, died with bird flu symptoms on Sunday after being treated at a Christian hospital in Bandung, the capital of West Java province, said Hadi Yusuf, head of the bird flu ward at the city's Hasan Sadikin hospital.

The dead man's brother, 20, and sister, 15, were being treated in Hasan Sadikin hospital. Tests by a government laboratory showed the surviving brother had bird flu, Yusuf said.

It was not clear whether samples from the dead brother had been taken for tests when he was treated, the doctor said. "The condition of the (other) brother is not good. He's on a ventilator," Yusuf told Reuters. Results for the girl were expected tomorrow, he said.

The brothers often bought dead chickens to feed their dog, but the girl had no known history of contact with chickens, the doctor said. "If it is true that the youngest did not touch chickens at all, and she had bird flu, we need to suspect she got it from the brothers," he said.

According to the World Health Organization (WHO), 146 of the 249 people confirmed as infected with H5N1 bird flu since 2003 have died. Those infected have come from countries ranging from China to Iraq to Djibouti. Indonesia, with 51 deaths, has the highest toll of any nation.

In Thailand, a 59-year-old man died of bird flu last month, the country's 17th victim of the virus since it swept through much of Asia in late 2003, a senior Health Ministry official said today. The man died on Aug. 10 in a north-eastern province near the Lao border after chickens at his house fell sick and died, the official said.

The virus mainly affects birds but experts fear it could mutate into a strain capable of killing millions of people in a global pandemic. This fear heightened in May when seven people in an extended family died of bird flu in Indonesia's North Sumatra province.