HANOI - Vietnam slaughtered thousands of birds in its two largest today, while other Asian nations boosted efforts to halt the spread of deadly avian flu.

China vowed to vaccinate its entire stock of 14 billion poultry against bird flu, with the government promising to help pay for the process.

The deadly H5N1 strain of bird flu is endemic in poultry in parts of Asia and has killed more than 60 people in the region.

The virus remains hard for people to catch, but experts fear it could mutate into a form which can be passed from person to person and trigger a pandemic in which millions could die.

Officials in Vietnam were racing against time to meet the government's deadline for ending poultry raising in the capital Hanoi and in Ho Chi Minh City, the country's commercial hub and largest urban centre.

Police, veterinarians and health workers, wearing masks and protective clothes, gathered at duck farms in Hoang Mai district on the edge of Hanoi where outbreaks were detected earlier.

"We are carrying out the city's decision to kill all the poultry inside the city," veterinary official Phi Thanh Hai said as 3,500 ducks quacked in bags after being rounded up at a pond next to the Red River.

Hanoi poultry farmers said they got compensation of 15,000 dong (US$0.95) for each destroyed duck, which cost 40,000 dong to raise. Forty-two people have died from bird flu in Vietnam.

Indonesia and Vietnam should be given more resources to help stamp out the spread of the virus, the head of a global animal health body said.

Bernard Vallat, director general of the World Organisation for Animal Health, urged vaccination of poultry.

"Early detection is the first line of defence in defeating the virus but Indonesia and Vietnam, which do not have enough resources and adequate organisation, were late in responding to bird flu," Vallat said during a visit to South Korea.

"They cannot manage this virus by just killing animals at this stage. It is too late. The solution is using vaccination." Indonesia, its resources stretched by the tsumani disaster last December, has largely resisted calls for a mass cull of chickens, saying it does not have funds to compensate owners.

China, battling several outbreaks of H5N1 among poultry, set itself the tough target of vaccinating billions of birds.

Jia Youling, director-general of the Agriculture Ministry's veterinary bureau, said the central government would cover 50 to 80 per cent of provinces' costs, the Xinhua news agency reported.

It gave no timetable for the inoculation campaign.

The nine outbreaks reported across China this autumn "have been basically brought under control", Jia was quoted as saying.

Migratory birds have carried the virus to eastern Europe and Kuwait and experts fear it will soon spread to Africa.

Britain said it believed an outbreak last month in a quarantine centre was caused by birds from Taiwan, rather than a parrot from South America, originally thought to be the carrier.

More than 50 birds from Taiwan died at the quarantine centre, the government said.

Officials said tissue samples from the finch-like mesias were pooled so it was impossible to say how many of the 53 dead birds had H5N1, although some did.

"H5N1 was, on the balance of probabilities, introduced into the facility by the mesias," an epidemiology report released by the government said.

- REUTERS