Hong Kong ordered a cull of poultry across the city's markets today in a bid to stop the spread of the H5N1 virus between birds scattered across the territory.
Officials last week found the bird flu virus at a poultry stall in one of the city's many "wet markets" and ordered the culling of 2,700 birds over the week.
Government officials said today the virus had since spread among the island's poultry population.
"We have not found any dead chickens with the virus - not yet. We have not had any human cases," said Cheng Siu-hing, director of agriculture, fisheries and conservation.
Officials estimated there were 3,500 live birds remaining at roughly 470 stores, stalls or markets across Hong Kong as of Tuesday evening.
Fears of the spread of infectious disease have run high since 2003, when an outbreak of Severe Acute Respiratory Syndrome (Sars) hit the city of seven million.
The city detected 21 birds with H5N1 last year and periodically clamps down on imports from neighbouring mainland China - home to the world's largest poultry population.
Since the H5N1 virus resurfaced in Asia in 2003, it has killed 241 people in a dozen countries, according to the World Health Organisation.