South Korea has reported 441 new coronavirus cases on Thursday, the highest spike in the number of single-day infections since March 7.
The new figure took the overall caseload in the country to 18,706 and was also a triple-digit growth for 14 straight days, according to a media report.
The cases were traced to services at the Sarang Jeil Church in Seoul and also a massive rally held in the capital city on August 15.
The infections linked to the Sarang Jeil Church totalled to 939, while those linked to the August 15 rally rose to 219.
Seven were imported from overseas, lifting the combined figure to 2,770.
A total of 93 more patients were discharged from quarantine after making full recovery, taking the overall number to 14,461.
The country has been held up as a global model in how to curb the virus and rushed to contain new infections as life returned to normal.
Some high schools were forced to turn back pupils shortly after resuming classes early in June over concerns of new virus cases in their neighbourhood.
South Korea endured one of the worst early outbreaks of the disease outside mainland China, and while it never imposed a compulsory lockdown, strict social distancing had been widely observed since March.