Tokyo, Oct. 23 -- Authorities in the Japanese northern prefecture of Hokkaido have confirmed the first outbreak of avian influenza in the country this season, local media reported.

At a poultry farm in the town of Shiraoi, where the case was found, local authorities on Wednesday started to kill and dispose of some 459,000 chickens and placed a ban on the transportation of 620,000 hens at four other farms inside a ten-kilometer radius, public broadcaster NHK reported.

Workers at the farm in question found several dead chickens on Tuesday, with preliminary testing detecting the bird flu virus, the report said.

The prefectural government convened an emergency meeting on Wednesday morning. It was reported that genetic tests revealed the bird...