This photo, taken Tuesday, shows the COVID-19 screening checkpoint at the arrivals hall of Terminal 1 at Incheon International Airport. (Yonhap News)

South Korea reported 688 new cases of COVID-19 Wednesday, recording the highest number of cases in 89 days since 674 on Jan. 8.

According to the Korea Disease Control and Prevention Agency (KDCA), 653 of the cases were domestic transmissions while the remaining 15 were imported from overseas. The daily caseload went above 600 for the first time since Feb. 18. The country’s cumulative total is now 106,898.

Health authorities and experts say South Korea may soon face a fourth wave of COVID-19 infections. In the early stages of the third wave last December, the daily caseload reached 1,000 nine days after 628 cases were reported on Dec. 4.

The number of domestic transmissions increased by 193 compared to Tuesday, and the daily average number of domestic transmissions this past week was 524, passing the threshold of 400~500 for Level 2.5 social distancing.

A fourth wave will likely be bigger in scale than the third wave as infection waves tend to grow in size after each wave.

By Seo Hye-mi, staff reporter