South Korea's total COVID-19 caseload broke the 60,000 mark on Thursday as new cases have been rising at an alarming pace despite tougher virus curbs put in place ahead of the year-end holiday season.

New cases stood at 967 earlier in the day to raise the total to 60,740, according to the Korea Disease Control and Prevention Agency (KDCA), surpassing the threshold 11 months after the nation's first confirmed case on Jan. 20. A total of 900 people have died from the highly infectious virus.

It took only 10 days for the number to rise from 50,000 to top 60,000, marking the fastest ever pace of the pandemic in the nation.

The virus caseload rose from 20,000 on Sept. 1 to 30,000 on Nov. 20 and to 40,000 on Dec. 10.

Daily cases have hovered around 1,000 for the past week due mainly to mass cluster infections involving several senior care centers and a Seoul prison.

The daily number of cases first crossed 1,000 on Dec. 13 and hit a record high of 1,241 on Christmas Day, which was faster than authorities had expected.

The third wave of the pandemic has posed greater challenges to antivirus efforts as sporadic infections in various community settings make it harder to trace their transmission routes compared with previous outbreaks.

The country faced its first wave of the outbreak tied to a church in the southeastern city of Daegu in late February and early March. The second wave gripped the country in late August in connection with a church in northern Seoul and an anti-government rally.

The transmission of the virus has accelerated this month despite tougher restrictions as the winter season provides a more favorable environment to viruses and weakens people's immune systems.

Experts expressed worries over mass infections among senior care centers, which could sharply raise the number of critically ill patients and deaths.

"Elderly people suffering chronic illness are vulnerable to group infections and are more likely to suffer severe symptoms that can lead to deaths," Kim Woo-joo, an infectious disease specialist at Seoul's Korea University, said. "Senior care facilities do not have enough medical equipment and staff needed for COVID-19 patients with serious symptoms."

Adding woes to antivirus efforts, the country has reported five cases of a new coronavirus variant first reported in Britain.

The government said it will suspend all flights from London to Incheon until Jan. 7, while making all incoming passengers from Britain and South Africa submit documents that prove they tested negative for COVID-19.

The transmission of the virus has showed no signs of letup despite stringent virus curbs aimed at minimizing people's activities.

The Seoul metropolitan area has been applying Level 2.5 social distancing rules, the second highest under a five-tier scheme, and Level 2 rules in the rest of the country since Dec. 8.

As some people flouted or found loopholes in the distancing scheme, a new set of special virus rules targeting popular venues took effect last week ahead of the year-end holiday season.

The special measures ban gatherings of more than five people and shut down ski resorts and other famous winter destinations for sunrise.

On Sunday, health authorities said they will keep the current distancing scheme until Jan. 3 and decide whether to raise it to Level 3, near-lockdown measures, afterwards.

"We will collect opinions from government agencies and provincial governments on how to adjust the social distancing measures after the special virus measures end on Jan. 3," Sohn Young-rae, a senior health official, said in a briefing on COVID-19 response measures.

Level 3 can be adopted when locally transmitted cases hover between 800 and 1,000 for a week or the daily tally doubles from the previous day.

If the toughest curbs are imposed, more than 2 million shops and facilities will be ordered to shut down, according to officials. (Yonhap)