South Korea's new coronavirus cases stayed below 5,000 for the second straight day Tuesday, but the number of critically ill patients hit a fresh high as concerns about a surge fueled by the omicron variant continued to put heath officials on edge.

The country added 4,954 new COVID-19 infections, raising the total caseload to 482,310, according to the Korea Disease Control and Prevention Agency (KDCA).

The number of critically ill COVID-19 patients hit a record high of 774, up 47 from a day ago, stoking fears that overworked medical staffers are further stretched thin and some patients might not get enough and timely medical attention.

The death toll rose 64 to 3,957, the second-highest daily figure after 70 recorded on Saturday.

Daily infections soared to a record high of 5,352 cases on Saturday before falling to 5,127 on Sunday and 4,325 on Monday.

The government reimposed stricter virus-related restrictions on Monday to limit indoor gatherings and encourage more vaccinations in order to contain a surge in infections and the spread of the omicron variant. The measures will remain in effect until Jan. 2.

The KDCA has confirmed 36 omicron cases, up 12 from a day earlier.

Of the total cases, Seoul reported 2,120 new cases, while 1,321 cases came from the surrounding Gyeonggi Province and 251 from Incheon, 40 kilometers west of Seoul.

On the vaccination front, 83.2 percent of the country's 52 million population have at least received one shot of the vaccine, while 80.6 percent have received two shots. (Yonhap)