Officials in Japan have confirmed that a recent outbreak of bird flu at a poultry farm was the deadly H5N1 strain of the virus.
The findings came after thousands of chickens died at the farm
Almost 4,000 chickens died at a farm in Miyazaki on the southern island of Kyushu last week, and the remaining 8,000 birds were culled on Sunday.
Tests confirmed the presence of H5N1, an Agriculture Ministry statement said.
There were a number of H5N1 outbreaks in Japan in early 2004, but there have been no human deaths from the virus.
"The examination conducted at the National Institute of Animal Health confirmed that the bird flu virus detected in Miyazaki prefecture was the H5N1 strain," the ministry statement said.
The government has banned the shipment of eggs and chickens from farms within a 6 mile (10km) radius of the outbreak.
Health officials across Asia are on alert as a growing number of countries have reported cases in both birds and humans in recent weeks.
On Monday Thailand reported a new outbreak, while officials in nearby Vietnam said bird flu had reached a seventh province in the Mekong Delta region.
Four people have already died from the virus in Indonesia this year.
Since the H5N1 virus emerged in South East Asia in late 2003, it has claimed more than 150 lives around the world.
There are fears the virus could mutate to a form which could be easily passed from human to human, triggering a pandemic and potentially putting millions of lives at risk.