VAN, Turkey (Reuters) - A Turkish girl has died in eastern Turkey from suspected bird flu and if confirmed would be the fourth victim in the region this month, authorities said on Sunday.

Health officials awaiting results of tests on teenager Fatma Ozcan, who had been in serious condition for several days. The virus has already killed three siblings in the same area.

“She died. I will be making a statement shortly,” Huseyin Avni Sahin, chief doctor at Van university hospital, told Reuters.

The H5N1 virus has been found in wild birds and poultry across large parts of Turkey, particularly in poor villages stretching from Istanbul at the gates of Europe to Van near the Iranian and Iraqi borders.

Fatma’s brother Muhammet is also in Van hospital suffering from bird flu-like symptoms and is in critical condition. The siblings were brought to hospital after being in contact with sick chickens and were treated with the antiviral Tamiflu.

The World Health Organization (WHO) believes human victims have contracted the disease from close contact with infected poultry, in most cases children playing with birds or helping families kill them for food or sale.

The Turkish victims are the first human cases reported outside east Asia since H5N1 reemerged in 2003. The virus mostly affects birds but has infected about 150 people and killed at least 78.

Most of the dozen or so bird flu patients are not in critical conditions but are still receiving treatment, with three people released from hospital late this week, the WHO said.

Two children, 11 and 13, with bird flu-like symptoms have been hospitalized in Istanbul after coming into contact with chickens in Gebze town, state news agency Anatolian said on Saturday.

The children were being treated in hospital, but it was not immediately clear whether they had been tested for bird flu.

So far, bird flu has been confirmed only in poultry in Istanbul, a city of 12 million people on the edge of Europe.

Bird flu has swept across a third of the country since the start of the year. The authorities have culled 600,000 wild birds and poultry to try to contain the crisis. They have launched an information campaign.

Health officials are going from house to house, particularly in the east of Turkey, searching for birds to cull.

WHO doctors said there was no sign of human-to-human transmission in the Turkish outbreak.

However, experts from another U.N. body, the Food and Agriculture Organization (FAO), have said the virus risked becoming a constant problem in Turkey as it is in poultry in parts of Asia.

Turkey’s government has set up a committee to discuss the crisis that has hit the country’s US $3 billion poultry industry, which is at risk of collapse. It will come up with proposals shortly.

The United States is sending a team of animal and human health experts to Turkey to assess the avian flu situation there. They will join experts already on hand from the WHO, the U.S. Centers for Disease Control and Prevention and the FAO.

(Additional reporting by Daren Butler in Istanbul)