South Korea's new daily coronavirus cases surged to more than 2,100 on Thursday, as the virus spread is gaining ground amid efforts to ease the distancing rules and return to normalcy.

The country added 2,111 fresh COVID-19 cases, including 2,095 local infections, raising the total caseload to 358,412, the Korea Disease Control and Prevention Agency (KDCA) said.

It is the first time in 20 days that the daily caseload has surpassed the 2,000 mark. The daily count was 1,952 the previous day, 1,266 on Tuesday and 1,190 on Monday.

The daily infection tally has moved in the quadruple digits since July 7, including the record high of 3,272 cases on Sept. 25.

The death toll rose by 11 to 2,808. The fatality rate stood at 0.78 percent.

As of 9 p.m. Thursday, South Korea had reported 1,930 new cases, up two from the previous day. The country will likely see the total reach over 2,000 for the second straight day.

Cases are counted until midnight and announced the following morning.

The spike in infections came amid concerns that the country could see yet another virus resurgence as efforts are under way to restore daily life back to the pre-pandemic days, with the planned shift to the "living with COVID-19" scheme on Nov. 1.

Park Hyang, a senior health official, said in a briefing the spike appears to be caused by increased movements, eased antivirus measures, rising infections among the unvaccinated population and breakthrough cases of the vulnerable group. 

The government said it will start administering booster shots next month to people in their 50s, those aged between 18 and 49 with underlying illnesses, and people who received one dose of Johnson & Johnson's Janssen vaccines.

Pfizer and Moderna vaccines will mostly be used for booster shots. Those aged over 30 who have received Janssen shots can choose whether they want to be administered the same vaccine or a different one.

The additional vaccinations began in October for people aged over 60 and other essential medical personnel working at hospitals, nursing homes and COVID-19 treatment facilities.

The KDCA said the booster shots will not be counted for the planned "vaccine pass" system, which would require a vaccination certificate or a negative test result for entry into high-risk places.

Samsung Biologics Co., a major South Korean contract drugs manufacturer, began supplying the first batch of domestically produced Moderna vaccines in South Korea.

The first batch -- part of 2.43 million doses of Moderna vaccines to be manufactured at Samsung Biologics' third plant in Songdo -- will be used to administer both first and second shots, as well as booster shots, during the fourth quarter.

Some virus curbs have been already eased since Oct. 18 to allow people to gather in larger groups and certain businesses to operate longer hours.

More relaxed measures will come into force in phases and most virus restrictions will be lifted by the end of January next year, although basic preventive measures, like wearing masks indoors, will stay in effect.  

The chilly weather that makes people want to stay more indoors may also help spur the virus surge. Calls for vigilance have grown as many communities are expected to celebrate Halloween over the rest of this week.  

About 40.97 million people, or 79.8 percent of the country's 52-million population, had received their first COVID-19 vaccine shots as of Wednesday. The number of fully vaccinated people came to 36.97 million, or 72 percent.

Of the locally transmitted cases reported Thursday, Seoul had 788 cases, with the surrounding Gyeonggi Province logging 708 cases and Incheon, west of Seoul, 137 cases.

Sixteen cases came from overseas, putting the cumulative total at 15,040.

The total number of people released from quarantine after making full recoveries came to 330,853, up by 1,195 from a day earlier, the KDCA said. (Yonhap)