Health workers in South Korea have begun to cull thousands of chickens after a new bird flu outbreak was discovered near the capital, Seoul.
There have been several bird flu outbreaks recently in South Korea
Chickens began dying on Tuesday at a poultry farm near Ansung, 80 km (50 miles) south of Seoul, officials said.
The outbreak is the country's sixth since bird flu reappeared there three months ago after a three-year absence.
It is not yet known whether it is the H5N1 strain of the virus, which is potentially fatal to humans.
"Test results confirmed that breeding chickens at a farm in Iljuk village were infected with highly contagious bird flu virus," the agriculture ministry said in a statement.
The farm houses more than 130,000 chickens.
Officials have ordered an immediate cull of the birds and another 107,000 on 28 nearby farms.
That will bring to more than two million the number of birds slaughtered in the country since bird flu reappeared there in November 2006.
More than 160 people worldwide have died of the H5N1 strain of bird flu.
The World Health Organization has warned of a potential pandemic if the virus mutates to a form that can be more easily contracted by humans.