The authorities in Hong Kong yesterday continued the mammoth job of killing 1.2 million birds in a bid to stop the spread of a mystery flu virus.
The mass slaughter of poultry was under way as pressure mounted on the government to trace the source of the virus.
While the authorities have few clues about the origin of the flu strain, they say it could not affect humans.
However, the slaughter has been ordered to stop the strain from mixing with other viruses and possibly harming people.
This is the second time in less than four years that Hong Kong has been forced to slaughter its poultry because of disease. Six people died of a bird flu virus in 1997.
On that occasion the government ordered the killing of its entire poultry population of 1.4 million.
Over the weekend, all live poultry at local markets were gassed and yesterday the slaughtering of mature birds in rural areas was under way.
The slaughtering operation will take two weeks to complete and will cost the government HK$80 million (£9.23 million). This includes compensation it will have to pay the poultry trade.
Hong Kong has halted imports of poultry from mainland China, which supplies over 70 per cent of the approximately 100,000 fresh chickens consumed daily.
Chinese authorities have already denied responsibility for the flu outbreak in Hong Kong.
The Hong Kong government has not firmly indicated when the import ban would be lifted and when chickens would go on sale again in local markets.
Meanwhile, the Philippines has also banned Chinese poultry as a result of the virus.
However, the bans by Hong Kong and the Philippines will not have a major impact on Chinese poultry producers because such a small amount of poultry is exported.
China exported about 4,400 tonnes of frozen poultry in the first quarter of this year, of which more than 90 per cent was to Hong Kong.
This is a tiny figure compared to China's annual output of more than 11 million tonnes of poultry.
China's State Exit-Entry Inspection and Quarantine Bureau said yesterday there were no reported cases of bird flu in China so far.
Meanwhile, the US Poultry and Egg Export Council said yesterday the outbreak of "bird flu" in Hong Kong is unlikely to spread to other countries as authorities are acting swiftly to cull the territory's poultry population.