Tokyo: A highly pathogenic H5N6 strain was found in wild birds and poultry farms in multiple locations in Japan, reports said.
The Pacific island nation culled about 310,000 chickens on Tuesday Xinhua news reported.
Earlier about 40 chickens were found dead. Preliminary test showed positive for bird flu, and also confirmed the presence of a highly contagious strain.
The Niigata and Aomori administration ordered farms within 10 km of the poultry farms in question to stop transporting eggs and poultry out of the areas.
Japanese Prime Minister Shinzo Abe has instructed relevant government ministries and agencies to coordinate to deal with the matter.
Japan recently raised the country's bird flu alert to the maximum level 3.