People line up for COVID-19 tests at a testing facility in central Seoul, Wednesday. (Yonhap)

South Korea reported nearly 400,000 new cases and record high deaths Thursday as the omicron variant is tightening its grip on the country, sickening nearly 20 percent of the 52 million population.

The country reported 395,598 new infections as of midnight, raising the total caseload to 10,822,836, the Korea Disease Control and Prevention Agency (KDCA) said.

While the daily tally was a sharp drop from the previous day's 490,881, which was the second-highest daily caseload, deaths hit a new record of 470. The total deaths from COVID-19 came to 13,902, and the fatality rate came to 0.13 percent, the KDCA said.

The number of critically ill patients stood at 1,081, down three from the previous day.

South Korea is experiencing the worst wave of the pandemic, surpassing the grim milestone of 10 million infections earlier this week. Nearly 9 million cases have been reported since early February. The daily caseload surged to an all-time high of 621,205 last Thursday.

The spread of the virus is feared to continue unabated amid relaxed social distancing rules. Earlier this week, the government eased some of its virus-related regulations to support retail and service sectors bearing the brunt of the pandemic's financial impact.

Health authorities warned the "stealth omicron" could continue to fuel a surge in infections despite earlier projections that the current wave could soon peak. The subvariant is known to be more transmissible than the omicron variant.

Amid rapid outbreaks among young children, the government has rolled out a vaccination program for children aged 5-11. Parents can make a reservation for a COVID-19 shot starting Thursday and vaccinations will begin next Thursday nationwide.

Also, an additional 44,000 doses of Pfizer's antiviral pills, Paxlovid, are set to arrive in the country Friday morning. The pills have been administered to some 100,000 patients so far.

MSD's drug Lagevrio, the second oral pill to be used to treat COVID-19 in South Korea, will start to be administered to patients Saturday.

The hospital bed occupancy rate for seriously ill COVID-19 patients came to 64.6 percent Thursday. The rate still remains manageable within the country's medical response capacity, according to the KDCA.

The number of people receiving at-home treatment stood at 1,873,582, up 408,031 from the previous day.

Of the domestic cases, Seoul reported 77,768 new infections, with the surrounding Gyeonggi Province logging 107,472. The western port city of Incheon reported 24,689.

As of midnight Monday, 32.48 million people out of the total population, or 63.3 percent, had received booster shots. Fully vaccinated people came to 44.46 million, representing 86.6 percent, the KDCA said. (Yonhap)