North Korea (search) acknowledged an outbreak of bird flu (search) for the first time, saying Sunday that hundreds of thousands of chickens were killed to prevent its spread, and the disease was not passed on to humans.

The outbreaks occurred at a "few chicken farms," and "hundreds of thousands of infected chickens" were burned before burial, the North's official Korean Central News Agency reported.

The short report said no breeders who work at the farms were known to have been infected.

"A dynamic work is now under way in different parts of the country to combat bird flu that plagues the world," KCNA reported, adding that government ministries were working to contain the disease's spread.

The report did not say which strain of the virus had been discovered.

Earlier this month, South Korea's Yonhap news agency reported that bird flu had broken out in the North, and South Korean officials said a trading company here delayed plans to import 40 tons of poultry from North Korea but declined to say why. Japan also banned poultry imports from the North after the report.

The North said last year it was strengthening quarantine measures against bird flu following the outbreak of the virus in Southeast Asian countries, but it had not previously acknowledged the disease was present in the country.

The deadly H5N1 strain of bird flu has spread through poultry farms in Southeast Asia since December 2003 and killed at least 48 people. Health officials fear it could mutate into a form more easily transmittable between humans that might result in a global pandemic killing millions.

The North already suffers from food shortages and relies on outside aid to feed its people, making the outbreak of bird flu a further blow to the isolated nation's food supply — devastated by years of poor harvests due to natural disasters and outdated farming equipment and practices.

On Saturday, the United Nations' World Food Program (search) launched a new appeal for food donations to North Korea, saying that a lack of supplies was forcing it to cut aid to children and the elderly. The WFP said it had already stopped giving vegetable oil to 900,000 elderly North Koreans and would reduce supplies to schoolchildren next week.

Nations, including the United States and South Korea, have continued providing food aid to North Korea despite an international standoff over the North's ambitions to build nuclear weapons. The North declared itself a nuclear power last month and said it would indefinitely boycott international arms talks until Washington drops its "hostile" policy toward it.