South Korea on Friday confirmed an additional bird flu case at a farm near Seoul, despite a recent plunge in the number of suspected cases.

The farm ministry said tests showed that 30,000 birds at the egg-laying chicken farm in Yeoju, about 100 kilometers southeast of Seoul, were infected with the virulent H5N1 strain of the avian influenza (AI).

The farm was quarantined as of Wednesday after a large number of birds started to die. All chickens on the farm will be culled with quarantine authorities to check nearby farms for sick birds, the ministry said.

The outbreak is the first to be confirmed since Feb. 17 when another chicken farm in nearby Icheon was a hit by AI.

"After peaking in January, there have been only five confirmed H5N1 cases so far this month," a quarantine official said.

The latest case marks the 45th bird flu outbreak confirmed in the country since suspected cases were first reported on Dec. 29. In the past two months a record 5.5 million birds have been culled in five provinces.

Prior to the latest series of outbreaks, South Korea was hit by AI three times, with the last cases occurring in April 2008 and resulting in the culling of 34.5 million birds at a cost of around 32 billion won (US$28.4 million). Other outbreaks took place in the winter months of 2003-2004 and 2006-2007. (Yonhap News)