Bangkok, Thailand ? The World Health Organization insisted Wednesday the mass slaughter of infected poultry was key to controlling the outbreak of bird flu sweeping Asia, but Indonesia said it didn’t intend to order its farmers to kill their birds.

Two sisters in Vietnam became the latest human fatalities, bringing the death toll to 10. Most human cases have been traced to direct contact with sick birds, and many victims have been young children.

Health ministers from across Asia had an emergency meeting Wednesday in Bangkok to consider how to stop the disease, but they did not reach a consensus on destroying their livestock.

Tens of millions of chickens and ducks have died in Asia — from the disease or in government-ordered slaughters aimed at containing it.

Indonesia has not officially reported bird flu cases to the World Health Organization, but it announced Sunday it was combatting the virus. The head of the country’s agricultural quarantine agency, Budi Tri Akoso, said Wednesday that slaughtering infected birds would be left to the discretion of farmers. The Indonesian government is considering a vaccination campaign for poultry.

Three international agencies — The World Health Organization, the U.N. Food and Agriculture Organization and the World Organization for Animal Health — have urged killing birds as the best approach. Experts said there was no consensus that vaccination is enough to avert an epidemic, though it could be a potentially helpful addition to slaughter.

China said it has slaughtered some 14,000 livestock birds found within two miles of the stricken farms, and poultry from farms within three miles was quarantined.

Beijing said in the campaign against the virus, it had slaughtered nearly 60,000 chickens.

China and Laos reported their first cases of bird flu in poultry on Tuesday, with Beijing saying there was one confirmed case and several suspected ones among ducks in the southern region of Guangxi, bordering Vietnam.

Cambodia, Indonesia, Japan, Pakistan, South Korea and Taiwan also have suffered outbreaks. However, the virus that has killed flocks in Pakistan and Taiwan is a different, milder strain of avian flu, not the same kind that is a threat to people.