South Korea has completed the culling of 6.1 million poultry nationwide to curb the nationwide spread of highly pathogenic bird flu, as the total farm-related caseload reached 18, the agricultural ministry said Friday.

The destroyed poultry included 4 million chickens and 1.2 million quails, according to the Ministry of Agriculture, Food and Rural Affairs.

Under the local law, poultry within a 3-kilometer radius of farms infected with highly pathogenic bird flu must be culled.

South Korea has reported 18 bird flu cases at farms since November.

The virus has especially spread at a faster pace in South Jeolla Province, which accounted for six infections. Four were from North Jeolla Province.

Local authorities have been vigilant as the virus is expected to haunt local poultry farms down the road, with migratory birds set to continue flying into the country through early next year.

The country reported this year's first highly pathogenic avian influenza case from wild birds in late October. A total of 29 cases were confirmed from wild bird habitats across the country. (Yonhap)