SEOUL — A cluster of novel coronavirus infections centered on a sect in the South Korean city of Daegu leaped to 39 cases Thursday, with its mayor advising residents to stay indoors as the country's total spiked for the second successive day.

Almost half the country's patients are linked to a 61-year-old woman who is a member of the Daegu branch of the Shincheonji Church of Jesus, an entity often accused of being a cult.

She first developed a fever on Feb. 10 but reportedly twice refused to be tested for the coronavirus on the grounds that she had not recently traveled abroad, and attended at least four services before being diagnosed.

So far 37 other members of the sect have been confirmed as infected, and the woman is also believed to have contaminated another person at a hospital.

Daegu's municipal government said 1,001 Shincheonji members who were believed to have attended the same services as the woman had been asked to self-quarantine.

A total of 43 cases have been confirmed in the city and neighboring North Gyeongsang province, and Daegu mayor Kwon Young-jin urged residents: "Starting from today, please refrain from leaving your house as much as possible."

The emergency units at all four general hospitals in Daegu have been closed as a precaution, a city official told AFP.

The mayor's request is not binding but one online poster who said they were in the city tweeted: "I can't go out because of Shincheonji and it's driving me crazy. Convenience stores and elderly community centers are closed, it takes twice as long for food delivery. It's really making me insane."

The US Army garrison in the city — where around 10,000 soldiers, civilians and family members live or work — restricted access and instructed any US troops who had recently attended Shincheonji services to self-quarantine.

"Travel in and around Daegu is highly discouraged unless absolutely necessary," the garrison said Thursday in a Facebook post.

"Please avoid public places and public transportation, to include stores, restaurants, subways and other heavily congested areas."

Shincheonji closed down all its facilities nationwide.

"We are deeply sorry that because of one of our members, who thought of her condition as a cold because she had not traveled abroad, led to many in our church being infected and thereby caused concern to the local community," it said in a statement.

The Korea Centres for Disease Control and Prevention (KCDC) said in a statement that 31 new coronavirus cases had been confirmed nationwide. That took the national total to 82 — until Tuesday South Korea had only 31 confirmed infections. — AFP