A duck farm in the South Chungcheong Province city of Asan has reported cases of the highly pathogenic avian influenza(AI).

According to authorities on Thursday, the poultry farm with around 290-thousand ducks was the nation's 40th case involving the contagious H5N1 strain reported since last fall.

Immediately after the farm raised the alert, authorities began to restrict access to and from the area and cull the animals while conducting an epidemiological study.

With poultry farms reporting a string of AI cases among wild birds, the government is continuing to ask farmers to conduct daily disinfection through Sunday.