South Korean health officials disinfect a stream which migratory birds stay in winter temporarily, to prevent spread of bird flu in Pohang South Korea and Japan have ordered fresh culls of poultry stocks to contain outbreaks of avian flu, authorities in the two countries said. The South Korean Agriculture Ministry said on Monday it had ordered the cull of an additional 2.4 million birds, taking the total number to a record 18.4 million since the first outbreak of avian flu was reported at a farm on Nov. 18. It has called the outbreak of the highly pathogenic H5N6 strain of bird flu more severe than the H5N8 strain that spread across the country in 2014 and 2015 before being brought under control.