South Korea confirmed two more cases of highly pathogenic bird flu at a poultry farm in a southern region on Sunday amid growing concerns over the disease spreading nationwide despite tougher measures.

Avian influenza (AI) of H5N8 strain was found from samples collected from two duck farms in Yeongam county, 384 kilometers south of Seoul, according to the Ministry of Agriculture, Food and Rural Affairs.

It marked the country's 11th and 12th highly pathogenic AI case in domestic birds this year.

Authorities culled poultry within a 3-km radius of infected farms as part of preventive measures, and issued a standstill order in nearby farms for 30 days, the ministry said.

Highly pathogenic avian influenza is contagious and can cause severe illness and even death in poultry.

The country reported its first highly pathogenic case in 32 months in late October in Cheonan, 92 kilometers south of Seoul, from wild birds. (Yonhap)