In Hong Kong, the authorities have begun the mass slaughter of about one and a quarter million chickens on farms and in markets. The move is an attempt by the government to eliminate a new strain of influenza originally found in birds, but which has now started to infect people. From Hong Kong, Jill McGivering reports:

In markets throughout Hong Kong, chickens, and also other poultry kept with chickens, such as ducks, quail and geese, are now being killed by hand and their carcasses taken away by government officials for safe disposal.

Farms breeding chickens are being provided with canisters to gas their birds.

The whole operation is expected to take little more than 24 hours. Early tests of public opinion suggest the Hong Kong public is in favour of the move.

As the number of cases of bird flu has increased, public anxiety about the new virus has grown steadily and the authorities have come under pressure to act decisively.

Once all the birds have been killed, a cleansing and disinfecting programme will start under government supervision.

Imports of fresh chicken will only start again when all the cleaning has been carried out.

Compensation for farmers and retailers is still being negotiated, but with sales of chicken already badly damaged by the health crisis, the amount offered by the government is expected to be more than many farmers were earning on the open market.

As a result of new guidelines, all birds imported from mainland China, which provides about three-quarters of Hong Kong's present stock, will be subject to rigorous health tests.

In the meantime, investigations are continuing.

The international team of experts working on the new flu still doesn't know exactly how it is transmitted, but as the number of cases grows, the likelihood of human to human transmission is strengthening.

So far, 12 people are known to have contracted the virus.