South Korea reported two suspected cases of African swine fever on Sunday despite massive preventive measures across the country.

The first new suspected case was reported from a farm in Pocheon, just north of Seoul, according to the agriculture ministry. The second suspected ASF case came from Boryeong, some 160 kilometers southwest of Seoul, the ministry said.

South Korea has been implementing seamless disinfection efforts to stem the outbreak of ASF, including extending a lockdown on northern areas of the country and culling more pigs as part of preventive measures.

In less than three weeks since the country's first-ever outbreak of the deadly animal disease, South Korea has confirmed 13 ASF cases.

The ministry said earlier the extended standstill on all farms of Gyeonggi and Gangwon provinces currently in place was lifted earlier in the day.

"We need to step up disinfection efforts in the regions that reported confirmed cases ... and vehicles moving in and out of them need to be controlled," Agriculture Minister Kim Hyeon-soo said in a meeting with related officials.

While South Korea has been culling all pigs in a 3-kilometer radius of infected farms, the ministry said it aims to purchase all pigs outside that boundary in Paju and Gimpo to send them to slaughterhouses.

In a similar move, the ministry earlier culled all pigs on Ganghwa Island, located northwest of Seoul, where five of the confirmed cases were reported.

South Korea had culled more than 130,000 pigs as of Sunday morning, with the figure anticipated to exceed 150,000 when the remaining pigs are slaughtered.

Culling is considered the only way to prevent the spread of African swine fever, as no cures are currently known.

On Thursday, South Korea found traces of the deadly animal virus in a dead wild boar in the Demilitarized Zone bordering the North.

Whether the wild boars infected pigs here, however, remains uncertain, according to the ministry.

The first-ever ASF case in South Korea came about four months after North Korea reported its first confirmed case of the disease at a farm near its border with China to the World Organization for Animal Health.

All of the 13 confirmed cases were reported from north of Seoul, with quarantine officials focusing efforts on preventing the virus from traveling to other regions of South Korea. The country is estimated to be raising more than 10 million pigs.

The case has drawn attention, as the island is several hours by boat from mainland South Korea and no roads connecting the island to other areas exist. The seventh ASF case took place on Seogmo Island, a small, isolated part of Ganghwa, with quarantine officials struggling to find out how the virus reached there. (Yonhap)