South Korea's daily new coronavirus cases fell slightly Monday due to fewer tests over the weekend, but the daily caseload has stayed above 1,000 for nearly two weeks. prompting authorities to tighten virus curbs across the nation to contain the spread ahead of the summer holiday season.

The country added 1,252 COVID-19 cases, including 1,208 local infections, raising the total caseload to 179,203, according to the Korea Disease Control and Prevention Agency (KDCA).

The latest figure was down from 1,454 on Sunday due to fewer tests over the weekend, but it marked an all-time high for a Monday amid the fourth wave of the pandemic.

The daily caseload has remained above the 1,000 mark since July 7 due to the resurgence in the greater Seoul area, and it has been spreading across the nation despite the nation's vaccination drive.

The country added one more COVID-19 death, raising the death toll to 2,058.

The greater Seoul area, home to half of the country's 51.3 million population, has emerged as the virus hot spot due to continued infections in various settings, including schools, workplaces, restaurants, gyms, department stores and entertainment venues.

Over the past week, over 30 percent of new cases were untraceable, and the reproduction rate, which refers to the number of people a single patient can infect, came to 1.32, further complicating the antivirus efforts.

Health authorities expressed concerns over the fast spread of the more transmissible delta variant, which poses a greater challenge to antivirus efforts.

The nation has confirmed a total of 1,001 locally transmitted variant cases over the past one week, 71.8 percent of which were delta variant cases, the KDCA said.

In response to a sharp hike in new cases in non-capital areas, health authorities tightened the virus curbs to limit gatherings of more than four people across the nation, which is effective for two weeks starting Monday.

Since last week, the Seoul metropolitan area has been under the highest level of the four-tier distancing measures, which ban gatherings of more than two people after 6 p.m. and place a 10 p.m. curfew on restaurants, cafes and entertainment facilities.

Ahead of the peak summer season, the southern resort island of Jeju raised its social distancing to Level 3 and the eastern coastal city of Gangneung implemented the toughest distancing measures to cope with rising new cases among travelers.

A total of 247 sailors of the 301-strong Cheonghae unit on an anti-piracy mission in waters off Africa have tested positive for the coronavirus since it reported the first six cases last week, the Joint Chiefs of Staff (JCS) said. The figure was not yet included in the daily caseload.

In the wake of the worst-ever mass infection among service members, the government has sent two aerial tankers to Africa to bring back all the service members, who are expected to return home Tuesday.

Although Cheonghae unit soldiers aboard the Navy vessel are eligible for vaccinations supplied by the Seoul government, KDCA Director Jeong Eun-kyeong said it is believed that the service members were left out due to difficulties in vaccine transportation and vaccination aboard the ship.

Vaccines by Pfizer and Moderna should be delivered and stored in ultra-cold conditions, which require specialized freezers and facilities.

Health authorities said they will also closely monitor the testing results of members of the Korean Confederation of Trade Unions (KCTU), a major umbrella labor group that held a massive rally in downtown Seoul on July 3.

Around 8,000 members of the KCTU participated in the rally despite authorities' repeated calls to cancel it amid the pandemic, and they are now required to take COVID-19 tests under the KDCA's administrative order issued after three participants of the rally tested positive as of Monday.

A total of 16.1 million people, or 31.4 percent of the country's population, have received their first shots of COVID-19 vaccines, and 6.6 million people have been fully vaccinated, the KDCA said.

On Monday, health authorities began rolling out the first jab of Pfizer vaccines to high school seniors and teachers across the country as part of efforts to get ready for the national college entrance exam slated in mid-November.

Of the newly confirmed domestic cases, 413 were from Seoul, 336 from the surrounding Gyeonggi Province and 62 from the western port city of Incheon.

The southeastern port city of Busan and its surrounding South Gyeongsang Province each reported over 60 cases.

Imported cases came to 44, with 13 from Indonesia and seven from Turkey.

The total number of people released from quarantine after making full recoveries was 159,630, up 677 from a day earlier.

The number of patients in critical condition came to 185, down two from the previous day. (Yonhap)