SEOUL — South Korea's new coronavirus cases slowed on Thursday, but health authorities are still fretting over further community spread tied to entertainment facilities and a hospital.

The 12 new cases detected on Wednesday raised the total caseload to 11,122, according to the Korea Centres for Disease Control and Prevention (KCDC). Of them, 10 were local infections.

The country reported new 32 COVID-19 cases on Wednesday, marking an uptick in nine days, as it reeled from a steady rise in nightclub-related cases in Itaewon, a popular nightlife area in the capital.

South Korea has successfully flattened the virus curve with massive and swift testing, but sporadic cluster infections continue to complicate public health authorities' quarantine efforts.

Cases tied to clubs in Itaewon have not evolved into explosive infections but have continued to increase steadily. The total caseload linked to the Itaewon cluster reached at least 197 as of late Wednesday, according to the Seoul city government.

Itaewon emerged as a hotbed for infections after a 29-year-old man tested positive for COVID-19 on May 6 following visits to clubs in the district in early May.

The country continued to report secondary and tertiary transmissions linked to the Itaewon outbreak

Health authorities are also on alert over looming infections at a hospital in southern Seoul.

Since four nurses working at Samsung Medical Center, one of the country's five major general hospitals, were confirmed to be infected, health authorities have conducted tests on 1,207 people.

The KCDC said more related cases are likely to spring up, as transmission routes are still unknown.

It said on Wednesday the nurses may have been infected at shared spaces, such as changing rooms, in the hospital or through patients undergoing surgery.

The KCDC said it has yet to detect a link between their cases and those tied to nightclubs.

Health authorities remain alert over further community spread, as school began to reopen the previous day, starting with high school seniors.

But on the first day of school reopening, Incheon, west of Seoul, and Anseong, south of the capital, ordered third graders at 75 high schools to return home. Two high school students tested positive for COVID-19 in Incheon, in what could be infections tied to the Itaewon outbreak.

The country, meanwhile, added two imported cases and reported one additional death, raising the total death toll to 264. The fatality rate was 2.37 per cent.

The total number of people released from quarantine after full recoveries stood at 10,135, up 69 from the previous day.

Since January 3, the country, with a population of more than 50 million, has carried out 788,684 tests, including 12,251 the previous day. — YONHAP