Bird flu has killed five young people in Azerbaijan, the World Health Organisation (WHO) revealed today.
It is investigating whether some of the victims were infected collecting feathers from dead swans.
Confirmation of the deaths in Azerbaijan, which lies at the crossroads between Europe and Asia, takes the human toll from the virus to 103 since it re-emerged in late 2003.
Egypt reported its fourth suspected human case last Friday, but that has not been confirmed by the WHO.
Pakistan today became the latest country to confirm bird flu in poultry, saying the virus found in two flocks late last month was the highly pathogenic H5N1 strain.
Bird flu has spread with alarming speed in recent weeks as it pushes deeper into Africa, Europe and Asia.
Fears are growing the H5N1 flu virus will mutate and pass easily from one person to another but for the moment it remains difficult for people to catch it from infected birds.
"We don't see any human-to-human transmission [in Azerbaijan]. The exact source of exposure to the deadly virus is under investigation, which is focusing on defeathering of birds," WHO spokesman Dick Thompson said.
Four of those who died came from a settlement of around 800 homes in the Salyan region in the southeast of the country. Three were related and the fourth was a close friend of the family. The fifth victim came from Tarter in the west.
The WHO said an investigation in Salyan had found some evidence that carcasses of swans, dead for some weeks, may have been collected by residents for their feathers. Adolescent women and young girls usually pluck birds in the affected community, the WHO said.
The feathers are used in pillows. Four of those who died were young women aged between 17 and 21, while the other was a 16-year-old boy.