(ATTN: RECASTS headline, lead; ADDS details throughout, photo)
SEOUL, June 6 (Yonhap) -- South Korea reported the biggest number of new coronavirus cases in eight days Saturday, raising concerns over new cluster infections popping up across the densely populated greater Seoul area despite tightened quarantine efforts.
The country added 51 cases, the most since the 58 reported on May 29, bringing the country's total caseload to 11,719, according to the Korea Centers for Disease Control and Prevention (KCDC).
The latest data comes as South Korea is grappling with a string of group infections linked to religious gatherings, nightclubs and a distribution center in the metropolitan area since relaxing its social distancing scheme on May 6.
The number of new cases appeared to be flattening after hitting 79 on May 28. But the figure started to rise again due to infections reported at small churches in Incheon, west of Seoul, and Gyeonggi Province, which surrounds the capital.
Of the 43 non-imported cases reported Saturday, all but three were identified in Seoul and adjacent areas.
Seoul added 23 cases, while Incheon, west of Seoul, and Gyeonggi Province, surrounding the capital, each reported 10 and seven cases.
The KCDC said cases traced to online retailer Coupang's warehouse in Bucheon, west of Seoul, increased by six to 130 as of noon, while those linked to the small churches and religious sessions rose by four to 80.
New clusters also ballooned in the capital area.
Cases associated with Richway, a Seoul-based health product retailer that specializes in door-to-door sales for mostly elderly consumers, jumped by 13 to 42 cases, while 17 cases have been identified in relation to a ping pong club in the western Seoul ward of Yangcheon.
The Richway cluster is considered especially risky as a majority of the cases are elderly patients who are more vulnerable to the virus than the younger age groups.
The country's mortality rate for COVID-19 patients aged 80 or older stands at 26.2 percent, much higher than 2.3 percent for all ages.
Health authorities urged the public to strictly follow quarantine guidelines -- such as washing hands and wearing masks -- and refrain from group meetings, especially during the weekend.
"Today marks Memorial Day and is also a weekend, and I understand many religious events will be held across the country tomorrow. ... (I) request that religious events are held while strictly abiding by quarantine guidelines," KCDC Director Jeong Eun-kyeong said in a regular briefing, asking small religious events to be canceled or postponed, if possible.
Jeong said a probe into venues where infections occurred showed that quarantine guidelines were not followed and that singing or eating had taken place. A lot of the venues were also located in basements or confined spaces, making it difficult for air to flow.
Health authorities said they plan to tighten inspections of venues that were overlooked in the quarantine process to prevent additional outbreaks as seen in Richway and the religious events.
The sharp increase reported Saturday heightens concerns ahead of the fourth and final round of school reopening scheduled for Monday.
South Korea started resuming in-person classes in May, but schools in some areas have again returned to remote learning as new infections were reported.
It is also expected to put health authorities on alert over possibly tightening quarantine guidelines to contain the infectious virus.
Earlier, health authorities decided to reinforce social distancing guidelines for the metropolitan area, shuttering public facilities again and ordering entertainment establishments to refrain from opening until June 14.
But if the figures from the metropolitan area continue to rise, South Korea may have to consider a return to strict social distancing.
South Korea's COVID-19 death toll remained flat at 273, while the number of people released from quarantine after fully recovering totaled 10,531, up 25 from the previous day, according to the KCDC.
After six months, pandemic accelerates arrival of contactless future in S. Korea
Subscription models, another way out for slump-hit retailers amid contactless trend
One month into eased social distancing, S. Korea wrestles with cluster infections, cases with unknown routes
Virus outbreak sheds light on overlooked side of highly touted 'fast' delivery services
Livestreaming platform, another alternative tool for retailers in 'non-contact' era