"The area where new cases were found is near where previous cases were confirmed," an institute official said, adding that electrical fences will be installed to prevent further spread of the disease.

South Korea has begun to mobilize hundreds of soldiers and civilians to hunt down wild boars near the border to try to contain spread of African swine fever.

Earlier in the day, the South Korean military removed 126 wild boars in areas bordering North Korea in an intensive two-day operation.

In May, North Korea reported its first outbreak of the disease at a farm near its border with China to the World Organization for Animal Health. It remains unknown how the virus traveled into South Korea.

South Korea has confirmed 14 cases of African swine fever at local pig farms since Sept. 17, when the country confirmed its first case of the deadly hog disease at a farm near the border with North Korea. So far, all reported cases have been in areas bordering the North.

The virus is not harmful to humans but causes hemorrhagic fever in pigs that is almost always fatal. There is no antidote or vaccine and the only known way to prevent the disease from spreading is a mass cull of affected livestock.

South Korea, Asia's fourth-biggest pork consumer, has slaughtered and buried more than 150,000 pigs since the outbreak started. (Yonhap)