(ATTN: ADDS more info in paras 7-8, 10, additional photo; RECASTS 1st para to highlight omicron situation)
SEOUL, Dec. 2 (Yonhap) -- South Korea's daily coronavirus cases and the number of critically ill patients hit record highs Thursday amid deepening concerns over the potentially more transmissible omicron variant following its first confirmed infections a day earlier.
South Korea reported 5,266 new COVID-19 cases, including 5,242 local infections, raising the total caseload to 457,612, according to the Korea Disease Control and Prevention Agency (KDCA). It marked the second straight day that the number of new coronavirus cases has been above 5,000.
The country added 47 more deaths from COVID-19 on Thursday, raising the death toll to 3,705. The fatality rate stood at 0.81 percent.
The number of critically ill patients reached an all-time high of 733 on Thursday.
About 80 percent of the country's intensive care units are occupied with COVID-19 patients, with those infected under treatment at their homes reaching 11,000, the KDCA said.
On Wednesday, the number of new cases and serious cases breached the 5,000 mark and the 700 mark, respectively, for the first time since the country reported the first outbreak of COVID-19 early last year.
As of 6 p.m. Thursday, South Korea had added 2,720 new cases across the country, up 380 from the previous day. It is the largest ever tally as of the time since the first outbreak of the virus in January 2020.
Cases are counted until midnight and announced the following morning.
The emergence of the omicron variant has put a damper on 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.
Health authorities said Wednesday that they had detected the omicron variant in five people, including a fully vaccinated couple who had visited Nigeria last month.
The country had planned to further relax the virus curbs in mid-December after four weeks of the first phase.
But the government announced its decision on Monday to put the scheme on hold, saying the pandemic risk level, a new five-tier assessment system it introduced last week to evaluate the degree of COVID-19 risk, has reached the highest level in the country's capital area.
The government said it will speed up the administration of booster shots and secure more hospital beds over the next four weeks.
To contain the spread of the more transmissible variant cases, the government said Thursday it is considering adopting coronavirus restrictions similar to the toughest social distancing rules of Level 4, which among other things, ban gatherings of more than two people after 6 p.m.
To block the inflow of the omicron variant, all international arrivals will be required to undergo mandatory quarantine for 10 days for the next two weeks starting Friday, regardless of whether they are vaccinated, the KDCA said.
South Korean citizens and foreigners on long-term stay will be allowed to quarantine at home, while foreigners on short-term stay will have to be quarantined at a temporary facility designated by the government.
Health authorities will also test all foreign arrivals for the new virus strain if they test positive for COVID-19.
Of the locally transmitted cases, Seoul reported 2,262 new cases, and the surrounding Gyeonggi Province posted 1,490 more cases, followed by the western port city of Incheon with 354 cases.
The number of cases from overseas came to 24, raising the total to 15,795.
The KDCA said a total of 42.59 million people, or 82.9 percent of the country's population, have received their first shots of COVID-19 vaccines, and 41.13 million people, or 80.1 percent, have been fully vaccinated.
About 3.39 million people, or 6.6 percent of the population, have received a booster shot.