Deaths were reported on five farms in the Panyu district near Hong Kong starting Sept. 5. At least 9,830 ducks have since been reported dead, with tests on tissue samples at a provincial government lab showing the presence of the highly pathogenic H5N1 virus, the Agriculture Ministry said Sunday.
Hong Kong health secretary York Chow said late Monday the Agriculture Ministry has confirmed the cases as H5N1 bird flu.
As of Sept. 14, about 32,630 ducks had been slaughtered in an attempt to contain the outbreak.
China, which raises more poultry than any other country in the world, has vowed an aggressive fight against H5N1, which has sickened at least 328 people worldwide, killing 200 of them, according to the World Health Organization.
China has reported 25 human cases of bird flu since 2003, 16 of them fatal.
Experts have warned that if poultry outbreaks are not controlled, the virus may mutate into a form more easily passed between people, potentially resulting in millions of deaths.
Chow said Hong Kong will suspend chilled and frozen duck and geese from southern Guangdong province, where Panyu is located, for a week.
He said Hong Kong and Guangdong officials will also jointly inspect local farms that supply live chicken to Hong Kong and that Hong Kong will suspend live poultry and bird imports from farms located within a 20-kilometer (12.4-mile) radius of the site of the outbreak for three weeks.