South Korea reported 645 new cases on Wednesday, rising into the 600s for the first time since June 10th.
The figure includes 605 domestic transmissions and 40 imported cases.
It's the fourth day in a row that the number of imported cases has been 40 or higher amid concerns over coronavirus variants, especially the Delta variant, which was first detected in India.
However, Korean health authorities say that people fully vaccinated with two doses will have up to 88 percent protection from the variant.
Butthe Delta Plus variant is emerging as another challenge.
It was first detected in India in April and is known to bind to lung cells more easily and is potentially resistant to monoclonal antibody therapy.
The Delta Plus variant has been found in nine other countries so far, including the U.S., Japan, Poland and China.
As of Wednesday, no cases have been reported in Korea but health authorities say they are on alert.
An increase in outdoor activities and private gatherings are also seen as a major cause of the rise in the number of confirmed cases.
The city of Daejeon saw 57 cases on Wednesday, following cluster infections from private gatherings at a church and family gatherings.
Responding to this, the city has raised its social distancing level to one.five from Wednesday until end of this month.
Public facilities in Daejeon, including cafes, restaurants and indoor gyms are prohibited from operating between 11 PM and five AM.
Private gatherings of five or more people are prohibited, and events are limited to less than 100 people for the rest of June.
As South Korea is expecting the easing of social distancing measures from July first, the health ministry has urged people to not get slack over following the distancing rules, especially when it comes to private gatherings.
Seo Eunkyung, Arirang News.