South Korea's daily count of coronavirus cases topped 800 on Thursday, the highest since January 7, due to new cluster infections and the spread of the highly contagious Delta variant, officials said.

The government had relaxed social distancing measures starting this month as the daily tally had hovered around 500 over the past couple of months and the country's vaccination drive accelerated.

But just days before the eased curbs took effect, the numbers shot up to nearly 600 and then nearly 800 this week due chiefly to new outbreaks in the capital Seoul and its surrounding regions, prompting authorities there to postpone the easing by a week, Reuters reports.

“More than 80 per cent of new cases have come from the Seoul metropolitan area for a third straight day on the back of cluster infections from restaurants and private educational institutions,” Interior and Safety Minister Jeon Hae-cheol told an intra-agency Covid-19 meeting.