SEOUL (REUTERS, XINHUA) - Two people who posthumously tested positive for the highly contagious Omicron variant of the coronavirus appear to be the first such reported deaths in the country, Yonhap news agency reported on Monday (Jan 3).

Officials are still investigating the exact cause of death for the two patients, who were both in their 90s, Yonhap said, citing health authorities in the city of Gwangju.

South Korea reported 3,129 new cases of Covid-19 as of Sunday night compared to 24 hours ago, raising the total number of infections to 642,207.

The daily caseload was down from 3,832 in the previous day due to fewer virus tests over the weekend and tougher anti-virus measures, hovering below 4,000 for two days.

The recent resurgence was attributable to small cluster infections in the Seoul metropolitan area.

The number of the Omicron variant infections was 1,318 so far, including 703 imported cases and 615 domestic transmissions, up 111 from the prior day.

The country has administered Covid-19 vaccines to more than 44 million people, or 86.2 per cent of the total population.

The number of those who received booster shots was more than 18 million, or 36 per cent of the population.