South Korea raised its four-tier virus alert to the highest "red" level on Sunday as the number of COVID-19 infection cases soared to 602 in recent days with the death toll rising to five.

South Korean President Moon Jae-in chaired an emergency government meeting to tackle the virus spread, saying the infectious disease alert would be lifted to the highest level in order to strengthen the overall response system.

It marked the first time since the outbreak of the Influenza A (H1N1) in 2009 that the government issued the highest alert.

Under the red alert, the government is allowed to take tighter quarantine measures such as a ban on group activities and an order to temporarily close schools.

The education ministry ordered all preschools, primary and secondary schools nationwide to delay the opening day of the first semester by one week to March 9. It would consider further measures according to future situations.

President Moon said "a few days from now" would be a moment of great significance to combat the virus, ordering all government officials to take "unprecedented powerful" measures regardless of existing regulations.

As of 4:00 p.m. local time, the number of infected patients totaled 602, up 169 from the prior day. The Korea Centers for Disease Control and Prevention (KCDC) has updated the data twice a day at 10:00 a.m. and 5:00 p.m. local time.

The number of COVID-19 infections rose sharply in recent days, after 402 new cases were reported from Wednesday to Saturday.

Of the total patients, 494 were residents in Daegu, about 300 km southeast of the capital Seoul, and its surrounding North Gyeongsang province.

A total of 329 cases were linked to the church services of a minor religious group, called Sincheonji, in Daegu.

Among the 9,336 Sincheonji followers attending the church services, 1,276 showed symptoms of the virus infection, according to Yonhap news agency. The other 670 followers were not reached for contact.

Moon said the situations between "before and after" the group infections traced to Sincheonji were totally different, noting that if test for Sincheonji followers enters the final stage, the relevant figure would be reduced significantly.

The president stressed that it was unavoidable for local governments to temporarily close Sincheonji facilities across the country for the sake of public health and safety, asking the religious sect and its followers for cooperation.

He also asked other religious and general groups to refrain from crowded events both indoors and outdoors, saying trust and cooperation are the way to win the fight against virus.

Meanwhile, 111 cases were traced to Daenam Hospital in Cheongdo county, just south of Daegu. Test for all of 652 patients and medical staff was completed as almost all the patients at the hospital's psychiatric ward tested positive for the virus.

At the hospital, the first and second deaths from the COVID-19 virus were reported on Wednesday and Friday. The third death posthumously tested positive on Saturday.

Two more deaths were confirmed earlier in the day, raising the death toll to five.

The government designated Deagu and Cheongdo as a "special care zone" Friday, while protest rallies were banned in downtown areas of Seoul.

Since Jan. 3, the country has tested more than 25,000 people, among whom 17,520 tested negative for the COVID-19 virus and 8,057 were being checked.