South Korea's daily number of new coronavirus cases dropped below 40 Saturday, amid a stepped-up push to contain cluster infections traced to a distribution center just west of Seoul and fend off a potential virus resurgence.

The country logged 39 additional COVID-19 cases, down 19 from the previous day, bringing the total caseload to 11,441, according to the Korea Centers for Disease Control and Prevention (KCDC).

The latest tally marked a drop from the nearly two-month high of 79 on Thursday. But the authorities remained on high alert amid concerns recent bouts of infections could hamper efforts to return to normal after months of the grueling fight against the pandemic that has disrupted daily life and dented economic growth.

In a renewed plea for public cooperation, KCDC Deputy Director Kwon Joon-wook said that the next two weeks will be a "crucial juncture" in flattening the infection curve.

"We need to take greater caution, particularly in the densely populated Seoul metropolitan area," he told a regular press briefing.

"When the scale of COVID-19 infections grows, the virus could infiltrate medical, welfare and religious facilities where there are many vulnerable classes of people," he added.

He also said that there could "inevitably" be long-term restrictions imposed on operations of facilities that have not properly practiced everyday social distancing.

The slowdown in new infections appears to be attributable to the health and quarantine officials' aggressive campaign to stop the spread of infections from a distribution center of e-commerce leader Coupang in Bucheon, west of Seoul.

The facility has emerged as a focus of the country's containment campaign following mass infections traced to clubs and bars in the nightlife district of Itaewon in central Seoul.

As of 11 a.m. Saturday, the number of virus cases traced to the Coupang center was 108, an increase of six from a day earlier, the KCDC said, urging citizens to avoid large crowds and outdoor activities over the weekend.

All of the 108 cases were confirmed in Seoul and its surrounding areas. Of them, 73 patients are employees of the center with the remainder being people that came into close contact with them.

But when including another case that occurred in Bucheon after 11 a.m., the number of cases linked to the Coupang logistics center are estimated to be at least 109.

The number of infections linked to Itaewon clubs reached 269 as of noon Saturday, up three from the previous day, according to the KCDC.

"We are conducting tests on and putting into self-quarantine all the employees who have worked at the logistics center since May 12," Kwon said, adding that the number of infections may go up when considering that tests are still under way and that the incubation period of the coronavirus is 14 days.

The cases from the logistics center have laid bare the vulnerabilities of enclosed workplaces, particularly those where social distancing protocols are loosely applied due to heavy workloads.

The drop in new cases in Saturday's tally was a relief for the quarantine authorities fretful over the possible new wave of infections.

Late last week, the daily number of new cases hovered a little over 20 and then dropped below 20 early this week. But the figure shot up to 40 on Wednesday and to 79 the following day, with Friday's tally standing at 58.

Despite the slowdown, the health authorities remain wary of additional transmission, as a high-school third grader in the southeastern city of Busan was confirmed to have contracted the virus on Friday, the first case since schools recently started phased reopenings.

Authorities have yet to identify the high school senior's infection route, with screening tests of 125 people who were found to have contacted the student under way.

The KCDC said that 27 of Saturday's new cases were confirmed in Seoul and its surrounding areas, while the southern cities of Daegu and Gwangju reported two new cases each. Busan, South Jeolla Province and Gwangwon Province added one case apiece.

The country, meanwhile, added 12 imported cases and reported no additional deaths, with the total death toll staying at 269.

The total number of people released from quarantine after full recoveries stood at 10,398, up 35 from the previous day.

In related news, the defense ministry said that one of the 12 COVID-19 patients in the military, whose infections are linked to the Itaewon district, fully recovered from the infectious disease in the first such recovery case related to the cluster infection. (Yonhap)