An environment agency said Sunday it has found five more wild boars infected with the deadly African swine fever (ASF) virus in areas near the inter-Korean border. The discoveries raised the number of wild boar infections in the country to 325.

The five carcasses were found in border areas, including in the counties of Paju, Gunnae, and Yeoncheon in Gyeonggi Province, north of Seoul, according to a research institute affiliated with the environment ministry.

South Korea confirmed its first-ever outbreak of the animal disease in September last year. Although no additional ASF cases on farms have been reported since early October, authorities continue to discover dead wild boars carrying the disease.

Different from other animal diseases, such as foot-and-mouth disease, which is airborne, the African swine fever spreads through direct contact with infected animals or their remains, according to experts.

 North Korea reported its first outbreak of ASF at a pig farm near its border with China in May last year, and all confirmed cases so far in South Korea have been reported in border areas.

As part of preventive measures, the authorities have culled about 400,000 pigs. Currently, no vaccines or cures exist. (Yonhap)