China investigated mysterious reports of finches dropping dead from the sky and villagers in Indonesia set thousands of birds ablaze as they tried to rid the resort island of Bali of the deadly disease.
Ten countries are battling bird flu, culling 50 million chickens and other fowl as international health officials seek ways to contain a virus that has rapidly spread across half of the Asian continent.
Bird flu has jumped to people in Vietnam, where 13 have died, and Thailand, where the toll stands at five, with health officials tracing most of those cases directly to contact with sick birds.
But experts have said it's possible the virus jumped to people through another mammal, such as pigs, which have been implicated in human flu epidemics in the past. Swine are genetically more similar to humans than birds are.
Anton Rychener, representative for the U.N. Food and Agriculture Organization in Hanoi, said "nasal swabs taken from pigs have been positive for H5N1," the deadly strain of bird flu. "It continues to be under investigation and is of concern."
Other health officials expressed caution about reading too much into the early results.
Swab tests can easily be contaminated and are considered only to be a sign that further testing is needed. Finding the virus in the nostrils does not necessarily mean that the pig is infected. A more conclusive test would entail isolating the virus from blood samples of the pigs.
"It's just preliminary and no conclusion can be made at the moment," said John Rainford, spokesman for the World Health Organization in Bangkok. "We consider the probability that pigs can get infected and keep a close watch. But right now, there's no evidence that the virus is in pigs. It's too early to say that pigs are infected with H5N1."
Doctors in Vietnam on Friday announced two additional deaths, a 6-year-old girl from southern Dong Nai province and a 24-year-old man from central Lam Dong province.
Health experts at an emergency bird flu meeting overnight in Rome endorsed a strategy of vaccinating healthy chickens alongside the continuing slaughters of infected poultry that the World Health Organization has said is the best way to deal with the outbreak.
A widely available human vaccine is believed about six months away, but some bird vaccines are available now.
Indonesian villagers held an unusual Hindu cremation ceremony, meanwhile, aimed at ridding Bali island of bird flu, sprinkling thousands of sick chickens with holy water and then setting them ablaze.
The ceremony — normally reserved for burials of humans — is part of Indonesia's campaign to destroy as many as 10 million chickens. Bali is one of the country's hardest-hit provinces.
Health officials in eastern China were looking into a mass death of brambling finches, a migratory sparrow-like bird that winters throughout China.
One official in the Jiangsu province city of Taizhou, who gave her surname as Xu, said about 100 brambling finches fell dead from the sky in the city's Kou'an town. Blood samples were taken the same day but results were not yet available, she said.
Other accounts put the number of dead birds much higher, with one official saying about 6,000.
The head of the Kou'an town government, who gave his surname as Gao, said he doubted that number or that the birds died from flu.
"Since when do you see that many birds together all at once?" Gao said. "Maybe they all ate some poisonous food. Let's wait and see the results of the tests."
WHO has said the virus is believed to spread across regions via migratory birds, but exactly how it spreads is not well understood.
In Thailand, authorities prepared for a massive free chicken feast aimed at reviving the nation's ailing poultry industry.
Governments fighting the scourge are Thailand, China, Vietnam, Laos, Cambodia, Indonesia, Japan, South Korea, Pakistan and Taiwan. The strain afflicting Pakistan and Taiwan, however, is milder and not considered dangerous to humans.
There's been no evidence of people contracting bird flu from properly cooked chicken meat or eggs, but countries worldwide have slapped affected countries with bans on imports ranging from live poultry — a disease risk — to cooked poultry products — which experts say pose no risk.
Vietnam this week slapped a ban on all poultry sales.
Health officials are concerned that the bird flu could infect a person already suffering from a human flu, and that the two diseases could create a hybrid with bird flu's deadliness and human flu's contagiousness, sparking the next pandemic. That hasn't happened yet, they have said.