The daily COVID-19 increase in South Korea remained in the 600s for the second day, amid recent signs of a resurgence following last week's Lunar New Year holiday.

The Korea Disease Control and Prevention Agency(KDCA) said as of 12:00 a.m. Thursday, 621 additional people tested positive, raising the country's cumulative total to 85-thousand-567.

Daily cases, which fluctuated in the 300s and 400s earlier this week, climbed back over 600 from Wednesday, roughly a month after hitting the same range from January 8 to 10.

Out of the new cases, 590 were local infections, 432 of which were in the Seoul metropolitan area. 

A portion of the local cases were related to two new clusters.

As of Wednesday afternoon, 115 cases were confirmed in connection to a plastic manufacturing plant in Namyangju, Gyeonggi Province. In the other cluster, 129 cases have been linked to a furnace factory in the central Chungcheong Province city of Asan.