Disinfection vehicles move busily near a layer hen farm in Yeoju, Gyeonggi Province, Dec. 27. Following the outbreak of highly pathogenic avian influenza (H5N1) at a layer hen farm the day before, Yeoju City is strengthening quarantine measures, including culling poultry farms within a 500-meter radius of the affected farm. Yonhap

Korea reported two additional cases of highly pathogenic avian influenza Monday, bringing the country's total number of outbreaks this season to 23, authorities said.

The new cases were detected at a broiler breeder farm in Dangjin, 79 kilometers south of Seoul, and a meat duck farm in Buan, 204 kilometers south of Seoul, according to the central disaster management headquarters for AI outbreaks.

Authorities are monitoring 69 poultry farms located within the quarantine zones of the two infected farms to prevent further spread, the anti-disaster office said. (Yonhap)