Fourteen outbreaks of highly pathogenic avian influenza have been reported in South Korea, affecting duck farms across the country.
The outbreaks are of the H5N6 strain, different from the H5N8 type of virus that has been spreading across Europe in the past few weeks.
Some 4,790 birds died directly from the disease while more than 180,000 birds were destroyed to control the spread of the disease.
To prevent the bird flu from spreading further, movement controls, screening, disinfection, and surveillance are now being conducted.
Meanwhile, Japan has culled 330,000 chickens and ducks because of bird flu as Prime Minister Shinzo Abe instructed government ministries and agencies to coordinate closely and quickly put in place quarantine measures.