Chickens at a farm in Ogawa, Ibaraki Prefecture, have tested positive for an antibody indicating they were infected with the H5 strain of avian flu in the past, the prefectural government said Saturday.
The prefectural government imposed a ban on taking chickens and eggs from within 5 km from the farm.
The farm will cull its approximately 90,000 chickens.
The prefecture had been testing chickens at the farm because its owner also runs a chicken farm in Mitsukaido, Ibaraki Prefecture, whose chickens tested positive for an antibody to the bird flu virus in June.