South Korea has reported 40 new cases of the coronavirus, its biggest daily jump in nearly 50 days, causing alarm in a country where millions of children have been returning to school.
Active tracing and testing had stabilised the country's outbreak from its March highs, which allowed officials to ease social distancing guidelines.
But a steady rise in cases in the greater capital area in recent weeks has raised concern as officials proceed with a phased reopening of schools.
High school seniors returned to schools last week. More than 2 million other students down to kindergarten age were expected to return to school on Wednesday.
The latest figures by the Korea Centres for Disease Control and Prevention brought national totals to 11,265 cases and 269 deaths from COVID-19.
All but four of the new cases came from the densely populated Seoul metropolitan area, where officials have been scrambling to stem transmissions linked to nightclubs, karaoke rooms and an e-commerce warehouse. Three cases were linked to international arrivals.
Australian Associated Press