The outbreak, confirmed Saturday, marks the country's eighth case of the virus this year, Seoul-based Yonhap News reported.
It came ahead of the three-day mid-autumn Chuseok holiday, set for Sept. 20-22, when families hold ritual thanks to their ancestors and visit their graves.
South Korean authorities investigating the affected farm implemented emergency quarantine measures to prevent the swine disease from spreading, according to the news agency.
"Given the trend of ASF (African swine fever) outbreaks occurring frequently in autumn, there is a significant possibility of further outbreaks," said Kim Jong-ku from the Agriculture Ministry.
He also warned that the movement of a large number of people during the upcoming holidays could also heighten the risk of further spread.
African swine fever does not infect humans but is deadly and highly infectious among both domesticated and wild pigs.
tribune.com.pk