South Korea's COVID-19 cases have been rising again due to a highly contagious new omicron subvariant in the East Asian country, local media said on Thursday.

During the past 24 hours, South Korea registered 39,196 new infections, the highest daily figure in a week, bringing the caseload to over 18.64 million, Yonhap News Agency reported.

With 16 more fatalities, the virus-related death toll also rose to 24,696.

According to the Korea Disease Control and Prevention Agency, the highly contagious omicron subvariant BA.5 has been fast spreading in the country.

The nationwide infections declined in recent weeks after they reached a peak of over 620,000 in mid-March when the country was hit by the omicron variant.

Health authorities warned that the country entered into a new virus wave and urged people to wear masks despite the easing of social distancing restrictions last month./agencies