A third Turkish child from the same family died of bird flu on Friday as the virus which has killed 74 people in east Asia reached the threshhold of Europe.

Hulya Kocyigit, 11, was the sister of Mehmet Ali, a 14-year-old boy who died last weekend, and of Fatma, 15, a girl who died on Thursday.

The children lived in a remote rural district of eastern Turkey near the Armenian border. Their six-year-old brother is also being treated for the same disease in the hospital.

Huseyin Avni Sahin, the head doctor at Van hospital where the children died, told CNN Turk 23 people were now being treated at his hospital for suspected bird flu.

The authorities said on Thursday that the victims being treated came from more than one province in eastern Turkey. "Fifteen of them are in bed, one in a critical condition. Eight are able to move about. Most of the patients are children," he said.

The deadly H5N1 bird flu virus remains hard for people to catch but there are fears it could mutate into a form easily transmitted among humans. Experts say a pandemic among humans could kill millions and cause massive economic losses.

The disease has killed 74 people in China and Southeast Asia since 2003. Like the east Asian victims, the Turkish children who died are known to have lived in close proximity with poultry.

In the dead children´s home town of Dogubayazit, near the Iranian and Armenian borders, an anxious crowd gathered outside the state agricultural offices to dump sackfuls of dead poultry or to ask for their poultry to be culled.

"After the deaths everybody is scared. We are all getting rid of our chickens and nobody dares eat their meat," said local trader Devlet Kaya.

Agriculture officials wearing face masks and protective white suits carried the sacks away to be culled and dumped in the municipal rubbish tip outside the town, where they are buried in a deep pit and covered with lime.

CULLING CONTINUES

One official said 3,500 poultry had been culled in the district so far and this figure was expected to reach 5,000 by the time the operation was completed on Saturday. However, officials said some families were trying to conceal some of their poultry. Rauf Ulusoy, the state´s representative in the town, said 14 people had been sent from the town for treatment in neighbouring Van since the outbreak first emerged at the end of December.

He said the authorities had prepared a leaflet for locals detailing the precautionary measures which they should take against the spread of bird flu and this was being distributed in the town.

Authorities have sent extra supplies of the Tamiflu medicine used against the disease to Van, which is about 800 km (500 miles) east of the capital Ankara.

The World Health Organisation (WHO) has provisionally backed the diagnosis that the children died of the H5N1 strain of bird flu but has said that more tests need to be carried out.

The WHO sent a team of experts to Turkey to help investigate the deaths at Ankara´s request and the European Commission said it had sent a veterinary expert to help tackle the outbreak. Samples from Turkish patients were being analysed in Britain.

The WHO, which had been expecting human cases after the virus was first detected among wild birds and poultry in Turkey and parts of southeast Europe late last year, said the latest cases did not mean a worldwide flu pandemic had become more likely.