A third child from the same family has died of the H5N1 strain of avian influenza, the Turkish government's news agency says.

Hulya Kocyigit, 11, died Friday in a hospital in the eastern city of Van near Iran, a day after her sister, Fatma, 15, died. Their brother Mehmet Ali, 14, died on Sunday.

The deaths mark the most westerly progress of bird flu and the first deaths outside Asia, where 74 people have died since 2003.

Turkish and World Health Organization officials were downplaying the deaths, emphasizing that they were not the beginning of a pandemic.

The disease was not spread from human to human, but from chickens to the children, they said.

The situation will become much more serious if the flu mutates so that it can be passed between humans.

The children, and their six-year-old brother who is recovering in hospital, were playing with chicken heads, Dr. Huseyin Avni Sahin told the Associated Press.

Many residents in eastern Turkey keep chickens, which live close to people.

The children's symptoms included fevers and coughing.

About 30 people in Turkey are being treated for what may be avian flu.

Turkish officials are slaughtering poultry in the area.