South Korea reported more than 50 new virus cases for the second day in a row Thursday as cluster infections piled up outside the Seoul metropolitan area, this time in Daejeon, a central city, with the country's virus fight at risk of losing hard-won gains.

The country added 54 cases, including 44 local infections, raising the total caseload to 12,904, according to the Korea Centers for Disease Control and Prevention (KCDC).

The tally marked a slight rise from 51 reported a day earlier.

South Korea added 43 new cases of COVID-19 on Tuesday and 42 cases on Monday.

The daily number of local infections was the highest in two weeks, since 51 new cases were reported on June 18.

Of the locally transmitted infections, 22 cases were newly identified in Gwangju, 330 kilometers southwest of Seoul. The city also reported a double-digit number of virus cases for the first time a day earlier.

Those linked to a Buddhist temple in Gwangju rose by a whopping 30 to reach 49 on Thursday.

The greater Seoul area reported 18 new cases. Daejeon, a central city, reported just one more infection.

Over the past two months, densely populated Seoul and the surrounding area, which house around half of the country's 51-million population, took up most of the newly added cases here.

South Korea, which relaxed strict social distancing in early May on the back of a flattened virus curve, decided last month to indefinitely apply toughened infection preventive measures in the greater Seoul area due to a continued rise in cluster infections tied to religious gatherings, warehouses and door-to-door businesses.

But the latest uptick in the number of cases from other areas outside the metropolitan area, including Gwangju, may prod health authorities to consider readopting the scheme elsewhere.

"As all areas of the country are within a day's reach, all regions are vulnerable to the COVID-19 pandemic," KDCD Deputy Director Kwon Joon-wook said in a briefing, again urging South Koreans to follow basic sanitary guidelines.

Earlier this week, two students at an elementary school in Daejeon tested positive after coming in contact with a peer.

Health authorities said that although the cases are still under epidemiological study, one of the two is highly likely to have been infected at the school, while the other caught COVID-19 elsewhere.

If confirmed, it would mark the first case of the virus being transmitted in a school in Korea.

The country have carried out tests on more than 300 students and teachers so far. No additional COVID-19 cases were confirmed yet.

As part of eased social distancing, school reopenings began in mid-May.

To prevent possible spread of the virus among students, Gwangju decided to shut down all of its schools through Friday. Students will take online classes instead.

Cases traced to a major church in Seoul's southwestern ward of Gwanak reached 33 as of Thursday, up one from a day earlier.

Some 14 residents at an apartment building north of Seoul have tested positive so far as well.

Over the past two weeks, around 10 percent of the newly added patients had unknown infection routes, according to health authorities.

The country reported no additional deaths, with the death toll staying at 282. The fatality rate was 2.19 percent.

The rate, however, reached a whopping 24.9 percent for patients in their 80s. No deaths have been reported among South Koreans aged 29 and below.

The number of new imported cases reached 10, marking a double-digit rise for the seventh consecutive day.

The total number of people released from quarantine after full recoveries stood at 11,684, up 71 from the previous day. This indicates more than 90 percent of the COVID-19 patients here have been cured.

The country has carried out 1,295,962 tests since Jan. 3.

Health authorities said they plans to provide remdesivir, an experimental drug conventionally used for Ebola, to two local COVID-19 patients later in the day.

Remdesivir is the first medication shown to have a therapeutic effect on COVID-19 patients since there is no scientifically proven treatment and no vaccine for the deadly illness. (Yonhap)