China has confirmed a new outbreak of bird flu and the death of two people diagnosed with the disease.
The new outbreak among quail on a farm in the province of Guizhou comes after 16,000 quail were exterminated near Guizhou's capital, Guiyang. They were later confirmed to have the H5N1 strain of the virus, and another 42,000 birds were culled to prevent its spread.
After the outbreak was detected the agriculture ministry sent an expert group to lead the prevention and control work.
The ministry said the outbreak had been brought under control but scientists fear the H5N1 strain, which had killed more than 70 people since late 2003 and is endemic in poultry across parts of Asia, could mutate into a form that can spread easily between people, leading to a human pandemic.
In a statement on its Web site on Tuesday, the World Health Organisation (WHO) said the victims in two human cases in China reported last month had subsequently died.
Of eight confirmed human cases of bird flu in China, five have now died, according to WHO figures.
The latest victim is a six-year-old boy from the central province of Hunan, who fell ill in December and is now in hospital. The boy's condition was critical and doctors were fighting to save his life, state media said.