South Korea's daily new coronavirus cases fell back below 400 on Monday due to fewer tests over the weekend, but health authorities warned of the continued emergence of cluster infections at religious facilities and workplaces.

The country reported 384 more COVID-19 cases, including 370 local infections, raising the total caseload to 102,141, the Korea Disease Control and Prevention Agency (KDCA) said.

The country added four more deaths from COVID-19, increasing the total to 1,726.

In South Korea, a third wave of infections, which began in mid-November last year, has shown little signs of slowing down, with the nation reporting daily cases that have hovered around 400 over the past week.

Health authorities have urged people to comply with containment rules as people's movements are expected to increase amid spring weather.

Health Minister Kwon Deok-cheol described the current spread of coronavirus infections as a "crisis," citing cluster infections at logistics centers, indoor sports facilities and door-to-door sales firms.

"We are now at a stage of crisis where the number of confirmed patients does not decrease," Kwon said.

As of Sunday, the reproduction rate fell to 1.85, which indicates that a single COVID-19 patient transmits the disease to more than one person. A day earlier, the rate was 2.09.

To contain the continued rise in new infections, health authorities extended the current Level 2 social distancing rules in the greater Seoul area, where more than half of the country's overall population resides, and Level 1.5 for the rest of the country for another two weeks until April 11.

Bans on gatherings of five or more people will continue, and restaurants and other public facilities in the greater Seoul area will be allowed to remain open till 10 p.m.

Since Feb. 26 when the country initiated its vaccination program, a total of 793,966 people have been given COVID-19 vaccine shots, including 11 on Sunday.

AstraZeneca's vaccine took up 733,586, while Pfizer's accounted for 60,380, according to the KDCA

A total of 10,347 cases of side effects after vaccinations have been reported, though 10,215 of them were mild symptoms.

A total of 21 deaths after vaccinations have been reported, according to the KDCA.

South Korea seeks to vaccinate 12 million people by June, and it aims to achieve herd immunity by November.

AstraZeneca COVID-19 shots for citizens aged 65 and older began earlier last week, and Pfizer vaccines are to be administered to people aged 75 and older starting next month.

Of the total 370 locally transmitted cases, Seoul reported 105, and Gyeonggi Province that surrounds the capital city saw 130 new patients. Incheon, 40 kilometers west of Seoul, reported 18 more cases. The number of imported cases came to 14, down from 20 the previous day.

Cases tied to a sauna in Jinju, South Gyeongsang Province, rose by five to 246, with cases involving an entertainment facility in Busan up 70 to 71 and cases related to a logistics center in Incheon up 19 to 20.

Adding concerns to the spread of the more transmissible strains, the country reported 40 more new cases of COVID-19 variants, including 22 local infections, raising total variant infections to 289.

Of the additional cases, 38 people were confirmed to have been infected with the coronavirus variant believed to have originated in Britain, according to the KDCA.

The number of patients with serious symptoms across the country reached 100, down from 104 the previous day, the KDCA said.

The total number of people released from quarantine after making full recoveries moved up 269 to 94,124. (Yonhap)