The presence of the bird flu virus was confirmed in China today prompting the World Health Organisation to describe the disease as a "serious global threat".
A second Thai boy died of the disease as countries tightened defences against a potential SARS-like epidemic.
The rapid spread of the virus - which has now been detected in 10 Asian countries and killed eight people - lead the World Health Organisation and two other international organisations to ask for money and expertise to fight an all-out war against it.
"This is a serious global threat to human health," said WHO chief Mr Lee Jong-Wook. "We must begin this hard, costly work now."
China's Xinhua news agency said H5N1 strain of the bird flu - which can cross to humans and has already killed eight people in neighbouring Vietnam and Thailand - had killed ducks in the southern province of Guanxi.
The province neighbours Laos, where a senior Agriculture Ministry staffer said the disease had struck the area around the capital, Vientiane, prompting alarm from health officials who say the counry's poor infratstructure may not be able to cope with containing it.
Veterinarians suspected the death of chickens at a farm in the central Chinese province of Hubei and of ducks at a farm in the southern province of Hunan were also caused by bird flu, Xinhua said.
The outbreak in China sparked immediate concern amongst WHO officials.
"Clearly it is of concern now that there is an outbreak here in China," said Dr Julie Hall, a WHO co-ordinator in Beijing. "It is very urgent that the matter is dealt with quickly."
Culls and quarantine of poultry should be implemented and human contact with animals limited in order to prevent the opportunity for the virus to transmit to humans, she said.
China's huge population and humans living in close proximity close to poultry, pigs and other livestock in farms across the country's southern regions alarm epidemiologists, who worry they will be cauldrons for the next big flu epidemic.
The great fear is that the H5N1 virus might mate with human influenza and unleash a pandemic among people with no immunity to it.
So far, there is no evidence of it passing from human to human and generating a new strain that could spark a pandemic. Humans infected so far are believed to have caught the virus directly from birds.