China's Ministry of Agriculture notified the administration that the birds tested positive for the H5N1 bird flu virus, marking the country's fifth outbreak among poultry this year, Hong Kong's Food and Health Bureau said in a statement on Sunday.

The Ministry of Agriculture also said on its Web site that last week's outbreak in Guangzhou killed 114 poultry and resulted in the slaughter of 518 more birds. It has been contained, however, the ministry said.

China has reported three bird flu deaths among humans this year, including that of a 44-year-old migrant worker last month in southern Guangdong province. It has recorded 20 human deaths since the virus began ravaging Asian poultry stocks in late 2003.

China, which raises more poultry than any other country, has vowed to aggressively fight the virus that has killed at least 235 people worldwide, according to the World Health Organisation.

Scientists fear it could mutate into a form that spreads easily among humans, potentially sparking a pandemic that kills millions.

So far, most human cases have been linked to contact with infected birds.

Sunday's announcement came as Hong Kong is experiencing a bad year for seasonal human influenza. Last week, Secretary for Food and Health York Chow made an abrupt nighttime announcement that all kindergartens and grade schools would be closed for two weeks. The decision came after two children were infected with the flu and died.

Autopsies later confirmed that they suffered from underlying health conditions likely complicated by influenza infection and that they were sickened by viruses circulating elsewhere in the region.

The decision was the most drastic public health precaution Hong Kong has taken since it was hit with severe acute respiratory syndrome five years ago. Sars killed 299 people in the territory and sparked public fear with many people donning surgical masks whenever they went outside. The virus killed nearly 800 people worldwide. -- AP