Hundreds of schools are shut, churches have told worshippers to stay away and some mass gatherings have been banned in South Korea as cases of a new coronavirus swelled in the country.

South Korea said two people have died and 204 have been infected with the virus, quadruple the number of cases it had two days earlier.

The multiplying caseload in South Korea showed the ease with which the illness, called Covid-19, can spread.

Though initial infections were linked to China, new ones have not involved international travel.

Covid-19: confirmed cases
(PA Graphics)

The World Health Organisation (WHO) warned that such clusters not directly linked to travel from China suggest that time may be running out to contain the outbreak.

“The window of opportunity is still there. But our window of opportunity is narrowing,” said WHO director-general Tedros Adhanom Ghebreyesus.

“We need to act quickly before it closes completely.”

Mr Tedros singled out Iran’s discovery of 18 cases and four deaths in two days – and that a traveller from Iran carried the virus to Lebanon, and another traveller from Iran to Canada.

“These dots are very concerning – take them as dots or trends,” he said.

South Korea Prime Minister Chung Se-kyun started a government meeting on the health emergency by saying: “We have entered an emergency phase.

“Our efforts until now had been focused on blocking the illness from entering the country. But we will now shift the focus on preventing the illness from spreading further in local communities.”

Daegu, a south-eastern city of 2.5 million people that is the country’s fourth largest, emerged as the focus of government efforts to contain the disease, and Mr Chung promised support to ease a shortage in hospital beds, medical personnel and equipment.

Daegu mayor Kwon Young-jin has urged residents to stay inside, even wearing masks at home, to stem further infection.

The first case in Daegu was reported on Tuesday, but by Friday the area had 152, including South Korea’s first two fatalities from Covid-19.

Nationwide, the numbers told of a ballooning problem.

There were 20 new cases reported on Wednesday, 53 on Thursday and 100 on Friday.

A worker wearing protective gear disinfects chairs as a precaution against the coronavirus at a subway station in Seoul, South Korea
A worker wearing protective gear disinfects chairs as a precaution against the coronavirus at a subway station in Seoul (Ahn Young-joon/AP)

The central government declared a “special management zone” around Daegu on Friday, which did not restrict movement of residents or supersede local officials’ power but served as official recognition of the problem.

A total of 110 infections have been confirmed in Daegu and surrounding areas, including South Korea’s first fatality from Covid-19.

Most of those cases have been linked to a single house of worship, a branch of the Shincheonji Church of Jesus, where a woman in her sixties attended two services before testing positive for the virus.

About 1,000 others who attended services with the woman have been isolated in their homes for screening, and health authorities said they are trying to monitor thousands of other church members.

All 74 sites operated by the Shincheonji Church have been closed and worshippers have been told to instead watch services online for a sect whose leader claims to be an angel of Christ, but who is dismissed by many outsiders as a cult leader.

Its teachings revolve largely around the Book of Revelation, a chapter of the New Testament known mostly for its apocalyptic foreshadowing.

Health and city officials say the woman eyed as a potential transmitter at the church had contact with some 1,160 people, both at the church and at a restaurant and a hospital where she was treated for injuries from a car accident.

People suspected of being infected with the new coronavirus talk to medical centre workers to receive tests in Daegu, South Korea
People talk to medical centre workers in Daegu (Kim Hyun-tae/Yonhap via AP)

That raised fears that South Korea – which before Wednesday had recorded just 31 cases of the virus – should brace for a further surge.

“I hope South Korea will do everything to contain this outbreak at this early stage,” said Tedros Adhanom Ghebreyesus, director general of the World Health Organisation.

Usually bustling city centre streets of Daegu were nearly deserted on Friday as people wearing face masks lined up at clinics seeking testing.

Eight hundred schools in the area, due to start a new academic year on March 2, delayed their openings by a week.

Elsewhere in the country, angst grew.

In the capital Seoul, major city centre rallies were banned, and fears of the virus led many to avoid shops and restaurants and instead eat at home and order necessities online.

Buses and subways were full of mask-clad commuters.

The first three cases in the country’s 600,000-member military also sprang up on separate bases on Friday, bringing added concern.

Passengers wear face masks on a subway train in Daegu, South Korea
Passengers wear face masks on a subway train in Daegu (Kim Hyun-tae/Yonhap via AP)

A sailor on Jeju Island, an army officer in North Chungcheong province and an air force officer on temporary assignment at the military headquarters in central South Korea all tested positive.

All had links to Daegu, officials said.

Globally, more than 76,000 people have been infected in 27 countries, and more than 2,200 have died.

Even as new alarms were sounded elsewhere in Asia, in China, where the vast majority of cases have occurred, officials have expressed optimism over the number of new infections, which has been trending downward.

China said on Friday 889 new cases were recorded in the preceding 24 hours and 118 additional deaths.