South Korea confirmed another case of the highly pathogenic avian influenza (AI) at a local poultry farm on Monday, raising concerns over the possible nationwide transmission of the disease. 

Authorities said on Monday that a suspected case at an egg farm in Yeoju, Gyeonggi Province tested positive for the highly pathogenic H5N8 strain of bird flu.

It marks the fourth case of AI reported at a local poultry farm this year since late November, when the nation reported the first such case in two years and eight months at a duck farm in Jeongeup in North Jeolla Province.

Quarantine authorities blocked access to the affected farm in Yeoju and began to cull poultry at the farm in a precautionary measure. 

A standstill order also has been issued for all poultry farms in the province, banning movement of poultry and related vehicles for 48 hours through 5 a.m. Wednesday. 

Another suspected case was reported on Monday at a quail farm in Eumseong, North Chungcheong Province. Authorities are looking into whether it is a highly pathogenic strain.