South Korea's daily new coronavirus cases remained in the mid-1,400s for the second day in a row Sunday on fewer tests over the weekend amid concerns about increased cases in non-capital areas, the imminent summer holiday season and the prevalence of the delta variant from India.

The country added 1,454 COVID-19 cases, an all-time high for a Sunday, including 1,402 local infections, raising the total caseload to 177,951, according to the Korea Disease Control and Prevention Agency (KDCA).

The figure was down one from 1,455 on Saturday. The daily caseload has stayed above the 1,000 mark since July 7 on the back of a surge in confirmed new cases in the greater Seoul area. It hit a new high of 1,615 on Wednesday.

The country added two more COVID-19 deaths, raising the death toll to 2,057. The fatality rate came to 1.16 percent.

The greater Seoul area, home to half of the country's 51.34 million population, has emerged as the hot spot for the recent spike in confirmed new cases.

Under the highest level of four-tier social distancing measures in the region since Monday, gatherings of more than two people are prohibited after 6 p.m., with entertainment facilities, such as nightclubs and bars, ordered to close and restaurants only allowed to operate till 10 p.m.

As new cases increased in non-capital areas, considered relatively safe from the virus, the health authorities are expected to announce a ban on the gatherings of five or more people in such regions.

A total of 16.13 million people, or 31.4 percent of the country's population, have received their first shots of COVID-19 vaccines as of Sunday.

The KDCA added that 6.56 million people have been fully vaccinated, accounting for 12.8 percent of the population.

Starting Monday, the health authorities will administer the first dose of Pfizer vaccines to high school seniors and teachers across the country.

Teachers and high school seniors, totaling 650,000, were selected as preferential groups for vaccinations as the students are slated to take the national college entrance exam in mid-November.

They are scheduled to get their second dose of the vaccines by mid-August.

Of the newly confirmed domestic cases, 523 were from Seoul, 373 from the surrounding Gyeonggi Province and 83 from the western port city of Incheon.

The southeastern port city of Busan added 70 new cases, and its neighboring South Gyeongsang Province found 99 more.

Imported cases, which also include South Korean nationals from overseas, came to 52.

By country, 12 cases came from arrivals from Indonesia, trailed by those from the Philippines and Indonesia with seven each.

The total number of people released from quarantine after making full recoveries was 158,953, up 993 from a day earlier. This indicates around 89.3 percent of the patients reported here have been fully cured.

The number of patients in critical condition came to 187, down two from the previous day. (Yonhap)