The latest confirmed cases were reported within a civilian control line near the border, according to the Ministry of Environment.
In contrast, no additional ASF infections from local pig farms have been reported since the 14th case was confirmed on Oct. 9. So far, all confirmed cases from wild and domestic pigs have come from areas bordering North Korea.
Quarantine officials have been making efforts to hunt down wild boars in the border areas, deploying hunters and installing traps.
In May, Pyongyang reported its first outbreak of the disease at a farm near its border with China to the World Organization for Animal Health.
Still, it remains unknown how the virus traveled into South Korea. The disease normally spreads through direct contact with infected animals.
The disease is fatal for pigs but does not affect humans. As there are no cures available, South Korea has been culling pigs within a 3-kilometer radius of infected farms to prevent the further spread of the virus.
Since mid-September, when South Korea suffered its first-ever outbreak, the country has culled more than 150,000 pigs. (Yonhap)