China has confirmed its first human death from bird flu.
A woman in the eastern province of Anhui died after being infected with the H5N1 strain of bird flu, the health ministry said.
It added that a boy in central China had also contracted the virus but had recovered. The two are China's first confirmed human bird flu cases.
The H5N1 virus has killed more than 60 people in South East Asia since the latest outbreak began in 2003.
The Chinese health ministry said the 24-year-old woman who died was a poultry worker.
The nine-year-old boy who recovered had developed pneumonia symptoms following an outbreak of bird flu in his village in Hunan province.
His sister also fell ill and died - it is suspected she too had bird flu, but her body was cremated before samples could be taken.
China has been hit by four bird flu outbreaks in three weeks
Outbreaks of the H5N1 strain among birds were first spotted in Vietnam and Thailand in 2003.
It spread to several other countries in the region and beyond, with reports of the disease among poultry in Russia and Kazakhstan in July 2005 - and outbreaks in Turkey and Romania.
China alone has reported 11 outbreaks among birds over the past month.
The authorities have culled millions of birds, but experts are warning that the virus is entrenched in parts of the country.
Beijing on Tuesday vowed to vaccinate all of the country's estimated 14 billion poultry, but it is feared wild birds could spread the virus.
The disease generally still does not transmit easily to humans, but fears of a pandemic have been reinforced by its spread.
The World Health Organisation's Dick Thompson said it was essential that surveillance efforts were stepped up around the world if the disease was to be kept under control.
"As this virus reaches out to Europe, probably soon into the Middle East and Africa, the change in the virus could occur anywhere," he told the BBC.
However he added that no mutation had occurred so far that would increase the likelihood of people passing on the virus to others.
"It's still very rare that humans get this virus, and there seems to be very limited, very few cases of human to human transmission."