Japan has confirmed a third outbreak of bird flu in January, this time at a poultry farm in the western part of the country.

Officials said Monday tests showed the presence of the H5 strain of the bird flu virus at the farm in Okayama prefecture, where around 40 chickens have died since last week.

They said further tests will be carried out to find out whether the virus was the deadly H5N1 strain.

On Friday, Japanese authorities confirmed an outbreak of the deadly virus in the country's south, where tens of thousands of birds on the affected poultry farm in Miyazaki prefecture have been culled.

Earlier this month in the same area, Japan confirmed its first outbreak of H5N1 in three years.

No human infections have been reported.

Bird flu has killed more than 150 people worldwide since its emergence in 2003.

Some information for this report was provided by AFP, AP and Reuters.