All schools in the greater Seoul area switched back to online classes full-time on Wednesday in line with a semi-lockdown enforced in the capital area due to the worsening coronavirus situation.

The Ministry of Education said the measure will remain in effect until July 25.

By then, most schools will be closed for summer vacation, officials said.

Meanwhile, cram schools will still offer in-person classes until 10 p.m., but must strictly follow distancing and health measures.

The ministry said surveillance testing will also be conducted more frequently at schools nationwide, under enhanced virus prevention measures.

High school teachers and senior students are expected to get vaccinated against COVID-19 soon, following cram school teachers who've recently started getting their first shots.