BEIJING - A suspected outbreak of bird flu has killed nearly 10,000 ducks in southern China's Guangdong province.

The Agriculture Ministry says deaths have been reported on five farms near Hong Kong, starting September 5.

It says tests on tissue samples at a provincial government lab show the presence of the highly pathogenic H5N1 virus.

Further testing is being conducted in Beijing to confirm the initial findings.

As of September 14, almost 33,000 ducks had been slaughtered in an attempt to contain the outbreak.

China has reported 25 human cases of bird flu since 2003, 16 of them fatal.

Experts have warned if poultry outbreaks are not controlled, the virus may mutate into a form more easily passed between people, potentially resulting in millions of deaths.