South Korea on Thursday confirmed 334 more coronavirus cases, bringing the total number of infections to 1,595, with 12 fatalities, authorities said.

The Korea Centers for Disease Control and Prevention (KCDC) said that of the new patients, 311 were residents in Daegu, about 300 km southeast of the capital Seoul, and its surrounding North Gyeongsang province, the two worst-hit areas, reports Xinhua news agency.

The total number of infections in Daegu and North Gyeongsang province increased to 1,338.

The virus infection increased in the past week, with 1,230 new cases reported between February 19-26.

The country raised its four-tier virus alert to the highest "red" level on Sunday.

Two clusters of infections in the country's southeastern region led to the recent viral spread.

As of Wednesday morning, 597 cases were linked to the church services of a minor religious group, called Sincheonji, in Daegu.

The other 114 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 government had designated Deagu and Cheongdo as a "special care zone" last week, while protest demonstrations were banned in downtown areas of Seoul.

Since January 3, the country has tested around 57,000 people, among whom 35,298 tested negative and 21,097 were being checked.