South Korea has said it will ramp up Covid-19 testing at schools after a sharp rise of infections among children, weeks ahead of a plan to fully reopen schools nationwide, Reuters reports.

"There is a growing concern as the frequency of new cluster outbreaks has been increasing, centred on educational facilities such as private tuition centres and schools," Interior and Safety Minister Jeon Hae-cheol said.

South Korea plans to fully reopen schools nationwide from November 22.

The country has reported 2,667 new cases in the last 24 hours, an increase of more than 1,000 from the day earlier. Nearly one-fourth of the new cases were found in teenagers, officials said.