Health authorities in South Korea said on Monday that they are in the midst of a "second wave" of Covid-19 infections around Seoul, driven by small but persistent outbreaks stemming from a holiday in May.

The Korea Centers for Disease Control and Prevention (KCDC) had previously said South Korea's first wave had never really ended.

But on Monday, KCDC director Jeong Eun-kyeong said it became clear that a holiday weekend in...