HANOI (Reuters) - Two more Vietnamese, a 12-year-old girl and a woman, are in hospital with suspected bird flu, the official Vietnam News Agency said on Tuesday.

The girl, who lives near a poultry slaughter house, was in an isolation ward on Monday in the northern city of Haiphong, the head of the city´s Health Department was quoted as saying.

The woman was taken to hospital in Hue the previous day and both were being tested to see if they had contracted the H5N1 virus which has killed 49 people in Asia.

The Haiphong hospital has been treating a couple and their three daughters who caught bird flu last month, the largest number of bird flu cases found together in Vietnam.

The Tien Phong newspaper said researchers at the National Institute for Hygiene and Epidemiology meanwhile were trying to find what had caused the acute pneumonia which killed a 34-year-old doctor in the northern province of Quang Ninh.

He fell sick on Friday, his breathing worsened quickly despite emergency treatment for Severe Acute Respiratory Syndrome (SARS), and he died on Sunday, the newspaper said.

Test results were expected by the end of this week. A SARS outbreak in 2003 killed nearly 800 people worldwide, including five in Vietnam.

On Monday, Vietnamese doctors said a 27-year-old woman had contracted bird flu after drinking duck blood, a local specialty, but was expected to survive.

The bird flu virus swept across much of Asia in late 2003 and has since killed 35 people in Vietnam, 14 since the disease broke out anew in the southern Mekong Delta in December.

The virus, which has also killed 12 Thais and two Cambodians, does not pass easily from bird to humans and eating infected fowl cooked properly is not dangerous.