On Wednesday, South Korea reported 284 news cases, the sharpest daily surge, bringing the total to 1,261, according to the Korea Center for Disease Control and Prevention (KCDC).
Of the total, the number of patients in Seoul confirmed by the KCDC reached 49, but city authorities recorded five more cases later in the day.
Around 80 percent of the confirmed cases currently trace to two clusters of infections -- one at a branch of a minor religious sect in Daegu, 300 kilometers southeast of the capital, and one at a hospital in the neighboring county of Cheongdo.
Seoul had reported sporadic cases across the capital, with no significant virus hotbeds reported. But after a pastor at Myungsung Church, one of city's megachurches that has a following of 80,000, was infected, fears that things could change have been rising.
The infected pastor is assumed to have contracted the virus during a Feb. 14 visit to the Cheongdo hospital where mass infections broke out. In the following week, he took part in several church events, including a Feb. 15 service that around 2,000 people attended.
The church has shut down all facilities and suspended its Sunday services for the time being, but concerns over a mass infection among the congregation at one of the country's biggest Presbyterian churches are heightening.
Gangdong Ward, where the church is located, plans to set up a checkup unit at the church and trace around 348 who are known to have been in direct contact with patients.
The situation got worse after Somang Presbyterian Church in Gangnam Ward, which has some 60,000 worshippers, reported a novel coronavirus infection.
The church said a COVID-19 patient living in Anyang, south of Seoul, is one of its registered members and he attended church services on Feb. 9 and 16.
This patient, a 46-year-old man, was confirmed to be infected on Tuesday. Health authorities said that the man returned home from Hong Kong on Jan. 22 and that on Feb. 19, he met a co-worker who had visited Daegu.
The church has already advised those who attended the Feb. 16 service to limit their outdoor activities until this Sunday.
"We have been in talks with the local government in Daegu to get a guideline on how they reacted to the mass outbreak at the Shincheonji church ... We will strive to make sure that the situation that occurred in Daegu will not be repeated," a Seoul city official said.
Concerns are also rising over infection at the Catholic University of Korea Eunpyeong St. Mary's Hospital in northwestern Seoul, where seven people, including a hospital employee, patients and a caretaker, have been affected, according to the city's data.
On Wednesday, the city announced additional measures to block the contagious virus from further spreading, including expanding areas in the city center where it has banned rallies for "the sake of public health and safety."
Previously, the city banned rallies at three public squares -- Cheonggye Plaza, Gwanghwamun Plaza and Seoul Plaza -- where conservative groups have hosted mass rallies protesting against the government.
Under the tightened measures that went into effect Wednesday, the no-rally zone expands to the plaza in front of Seoul Station as well as the three-way intersection near the presidential office Cheong Wa Dae and parts of Gwanghwamun and Jongno.
Seoul police warned that any groups, including a conservative one critical of the Moon Jae-in administration, will face stern measures if they press ahead with rallies as planned this weekend.
City officials also plan to verify a full list of the religious sect's congregation once they get it from the central government and provide advice to Shincheonji followers.
Earlier in the day, Vice Health Minister Kim Gang-lip said the government had secured a list of 212,000 followers and will soon share the list with local governments.
There are nearly 30,000 Shincheonji followers in the capital. Mayor Park Won-soon said the city has secured a list of 28,300 Shincheonji members living in Seoul and that authorities will check all of them by Thursday.
source: Yonhap News