Quarantine workers culled the ducks between Nov. 18 and Friday, said an official handling the issue at the Ministry of Agriculture, Food and Rural Affairs. He asked not to be identified.
The culling came after the highly pathogenic H5N6 strain hit four duck farms in Jeongeup, Gochang and Yeongam in the country's southwest.
Kim Yung-rok, head of the Ministry of Agriculture, Food and Rural Affairs, held a meeting with officials earlier in the day and called for disinfection measures at each farm to stem the spread of bird flu.
Highly pathogenic avian influenza refers to viruses that cause severe disease in birds and result in high death rates, according to the World Health Organization.
Last year, South Korea slaughtered more than 30 million birds to contain the worst outbreak of bird flu in the country's history. Source from the Yonhap.