South Korean quarantine authorities are preparing to slaughter more than 270,000 poultry after an outbreak of a virulent strain of bird flu.
There have been several bird flu outbreaks recently in South Korea
Animal health experts have not yet determined if it is the H5N1 strain, which is potentially fatal to humans.
The latest outbreak, in the centre of South Korea, is the fifth since the virus reappeared in the country in November after a three year absence.
More than 160 people worldwide have died of the H5N1 strain of bird flu.
The latest outbreak has been detected in a poultry farm in Chonan, 90km (55 miles) south of the capital Seoul.
Chickens and other poultry are to be slaughtered within 500m (547yds) of the farm.
Hundreds of thousands of chickens were culled last November when bird flu returned to South Korea.
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.