Areas within three kilometres of a farm in China's Hebei province, the site of an H5N2 bird flu outbreak in poultry, have been sealed off, authorities said Sunday.
The disease killed 4,000 chickens raised at a farm in Baoding city after they showed symptoms of suspected avian flu Dec 17, Xinhua reported citing agriculture ministry.
The National Avian Influenza Reference Laboratory Saturday confirmed the epidemic was caused by the H5N2 avian influenza virus after testing samples collected at the farm.
Authorities sealed off and sterilised the infected area, where a total of 125,700 chickens have been culled and safely disposed of to prevent the disease from spreading.
Bird flu, or avian influenza, is a contagious disease of animal origin caused by viruses that normally only infect birds and, less commonly, pigs. It can be fatal to humans.