South Korea's daily coronavirus cases fell below 5,000 on Friday, but the number of critically ill patients hit yet another record high as the country prepares to limit private gatherings amid growing concerns over the new omicron variant.

The country reported 4,944 new COVID-19 cases, including 4,923 local infections, raising the total caseload to 462,555, according to the Korea Disease Control and Prevention Agency (KDCA).

The number of critically ill patients came to 736, up from the previous record high of 733 on Thursday.

Friday's tally is down from 5,266 counted the previous day, which marked an all-time high since the country reported the first COVID-19 case in January last year. The daily cases had stayed above 5,000 for two consecutive days.

The death toll came to 3,739, up by 34 from a day earlier. The fatality rate stood at 0.81 percent.

The emergence of the potentially more transmissible variant is a setback to South Korea's efforts to return to normalcy with a gradual easing of virus restrictions under the "living with COVID-19" scheme that began last month.

Six omicron variant infections have been confirmed this week, and fears are growing the cases will rise quickly.

To contain the spread of the omicron variant, the government said it will limit private gatherings to six in the capital area and eight in other regions for four weeks starting next week. Currently, the cap is 10 people in the capital area and 12 in other regions.

Restaurants and cafes will be added to the list of facilities requiring proof of vaccination or a negative test for entry.

A one-week grace period will be allowed before enforcing the rules.

The country had planned to further relax the virus curbs later this month, but the government decided to put the scheme on hold, citing the high risks of the pandemic and variant concerns.

Beginning Friday, all international arrivals are required to undergo a mandatory quarantine for 10 days for the next two weeks, regardless of whether they are vaccinated.

Of the locally transmitted cases Friday, Seoul reported 2,094 new cases, and the surrounding Gyeonggi Province posted 1,464.

The number of cases from overseas came to 21, raising the total to 15,817.

The KDCA said 42.61 million people, or 83 percent of the country's population, have received their first shots of COVID-19 vaccines, and 41.19 million people, or 80.2 percent, have been fully vaccinated.

About 3.57 million people, or 7 percent of the population, have received a booster shot. (Yonhap)