SEOUL - South Korea confirmed 813 more cases of the COVID-19 on Saturday, raising the total number of infections to 3,150.

As of 4:00 pm local time, the number of infected patients totaled 3,150, up 813 from the previous day. Four more deaths were reported, lifting the combined death toll to 17.

The virus infection jumped in recent days, with 2,306 new cases reported on Feb 19-28. The country has raised its four-tier virus alert to the highest "red" level.

The Korea Centers for Disease Control and Prevention (KCDC) has updated the data twice a day at 10:00 am and 5:00 pm local time.

Of the new patients, 657 were residents in Daegu, about 300 km southeast of the capital Seoul, and 79 came from its surrounding North Gyeongsang province.

The total number of infections in Daegu and North Gyeongsang province increased to 2,236 and 488 respectively.

Daegu became the epicenter of the viral spread here as the biggest cluster of mass infections was found in the city with a 2.4 million population.

The city ordered all of its 800 preschools, primary and secondary schools to postpone their March openings by two more weeks. The education ministry already delayed the opening of the first semester by a week to March 9.

The Daegu cluster was closely linked to the church services of a homegrown minor religious sect, called Sincheonji, in Daegu. As of Saturday morning, 1,557 cases were tied to the worship services.

Out of around 1,200 confirmed patients who were untraceable to the source of infection, most of the patients were believed to have been linked to the Sincheonji church services, the health authorities estimated.

The health authorities completed the test on about 1,300 members of the Sincheonji Daegu branch, who developed fever and other symptoms, and the test results would be announced by this weekend.

Among about 190,000 followers across the country to be available on the list offered by Sincheonji to the government, the health authorities checked about 170,000 followers. Of the total, 3,381 showed infection symptoms.

The health authorities asked people to stay home and refrain from going outside as this weekend is forecast to be the most significant period for the virus containment efforts.

A total of 119 cases were traced to Daenam Hospital in Cheongdo county, just south of Daegu. Test for all of about 650 patients and medical staff was completed as almost all of the patients at the hospital's psychiatric ward tested positive for the virus.

The cluster infection at the hospital was believed to have been linked to the Sincheonji sect as a number of followers attended a funeral ceremony for a brother of the Sincheonji founder.

The government has designated Daegu and Cheongdo as a "special care zone."

Two more patients were discharged from quarantine after making full recovery, lifting the combined number to 28.

The 25th patient was discharged from hospital with recovery on Feb 22, but the 74-year-old woman tested positive again on Friday, becoming the first South Korean to be re-infected with the COVID-19.