China had insisted that it was free of the bird flu, but the government said Tuesday that the virus was found in dead ducks on a farm in a southern region that borders Vietnam.
No infections have been found in human beings in China, the official Xinhua News Agency said.
Some 14,000 birds within a two-mile radius of the farm were slaughtered, and a quarantine was imposed on poultry within three miles, Xinhua said.
Earlier, the World Health Organization warned workers to wear protective clothing and masks as they slaughter millions of chickens across Asia in a bid to control the spread of the disease and the fast-food chain KFC said it would offer customers in Vietnam fish instead of its signature chicken.
Australia, which remains free of the virus, urged other countries to immediately reveal bird-flu cases, following allegations that Thailand and Indonesia initially covered up outbreaks.
"Countries in the region must learn from the SARS experience, and that is: `Fess up as soon as you find a case, as quickly as possible," Australian Foreign Minister Alexander Downer told Australian Broadcasting
Corp. radio. "Make sure everybody knows about it and deal with it."
The virus has jumped to humans in two countries.
Thailand's Public Health Ministry confirmed that a six-year-old boy died from the disease Tuesday, becoming the country's second fatality and the region's eighth, following six deaths in Vietnam. Thai officials awaited lab results on five other deaths believed linked to the virus.
Thailand's first death, announced Monday, also was a six-year-old boy, who had carried a dying chicken to a butcher.
Thai officials planned an international meeting Wednesday in Bangkok to discuss strategies for combating the illness. Nearly a dozen governments, including China, United States and the European Union, were expected to send representatives, Thai officials said.
The scope of this year's outbreak has widened alarmingly, with countries reporting new outbreaks in poultry stocks for each of the past three days.
Indonesia joined the list of affected countries on Sunday, 완주출장안마
Pakistan on Monday and Laos on Tuesday. The Laos Livestock Department director Singkham Phounvisay said tests confirmed the virus there after reports of hundreds of chickens being sickened.
So far, 10 governments have reported some strain of bird flu: China, Cambodia, Indonesia, Japan, Laos, Pakistan, South Korea, Taiwan, Thailand and Vietnam. Some countries claim their version of bird flu is milder than the one that has jumped to humans.
The World Health Organization believes the virus can be transmitted across regions by migratory water fowl.
Tens of millions of chicken and other poultry have been infected in recent weeks, prompting the slaughter of chickens at farms across the region to contain the virus. South Korea alone has killed 24 million chickens and ducks since its outbreak surfaced in December.
WHO said the virus has mutated since an outbreak in Hong Kong in 1997, when six people were killed in the first documented case of the virus jumping to humans and the deadliest episode until this year's outbreak.
The mutations complicate the search for a vaccine. The virus strain isolated from the 1997 outbreak can no longer be used to produce the medicine, the health organization said.
Scientists believe people get the disease through contact with sick birds. Although there has been no evidence of human-to-human transmission in the latest outbreak, health officials are concerned the disease might mutate further and link with regular influenza to create a form that could trigger the next human flu pandemic.
Following weeks of denials in Thailand, the government confirmed on Friday that the disease had struck the Thai countryside, sparking allegations of a cover-up.
"The government knew, so why didn't they tell the public so that we could protect ourselves?" said farmer Chamnan Boonmanut, whose 6-year-old son Captan Boonmanut died from the disease.
Other farmers had alleged for weeks that the government was hushing up Thailand's outbreak to protect poultry exports, and said flu vaccines for chickens might have stemmed the problem.
The European Union criticized Thailand for "non-transparency" in dealing with the outbreak and said it would demand independent verification that bird flu had been eradicated in Thailand before it lifts the ban on chicken imports imposed last week.
Indonesian officials have denied reports alleging that the government initially covered up an outbreak at the behest of companies with poultry export interests.
The allegations have led to comparisons with last year's worldwide outbreak of severe acute respiratory syndrome, which emerged in late 2002 in southern China. Critics faulted China for not being forthcoming enough about the disease during the early stages.