SEOUL, South Korea (AP) — South Korea reported an eight-fold jump in viral infections Saturday with more than 400 cases mostly linked to a church and a hospital, while the death toll in Iran climbed to six and a dozen towns in Italy effectively went into lockdowns as health officials around the world battle a new virus that has spread from China.

Some virus clusters have shown no direct link to travel to China. The spread in Italy prompted local authorities in the Lombardy and Veneto regions to order schools, businesses, and restaurants closed and to cancel sporting events and Masses. Hundreds of residents and workers who came into contact with an estimated 79 people confirmed infected in Italy were in isolation pending test results. Two people infected with the virus have died.

South Korea has reported 433 cases and its third death from the virus, a man in his 40s who was found dead at home and posthumously tested positive. There’s concern that the country’s death toll could grow. In and around South Korea’s fourth-largest city, Daegu, health workers scrambled to screen thousands. Virus patients with signs of pneumonia or other serious conditions at the Cheongdo hospital were transferred to other facilities, 17 of them in critical condition, Vice Health Minister Kim Gang-lip told reporters.

He said that the outbreak had entered a serious new phase, but still expressed cautious optimism that it can be contained to the region surrounding Daegu, where the first case was reported on Tuesday.

Globally, nearly 78,000 people have been infected in 29 countries, and more than 2,300 have died.

A team of global experts with the World Health Organizatio n is on the way to China’s Wuhan, the epicenter of the outbreak, WHO Director-General Tedros Adhanom Ghebreyesus said Saturday. It has been visiting other parts of China this week.

Tedros also told a meeting of African health ministers that the WHO is concerned about cases with “no clear epidemiological link, such as travel history to China or contact with a confirmed case.” He is especially concerned about the growing number of cases in Iran.

But Tedros said the top concern is the potential spread to countries with weaker health systems, including in Africa. The 20% of virus patients with severe or critical disease require intensive care equipment that is “in short supply in many African countries,” he said. Just one case of the virus has been confirmed in Africa, in Egypt.

In some positive news, China said Saturday that the daily count of new virus cases there fell significantly to 397, though another 109 people died of COVID-19, the disease caused by the virus. Most of the new cases and all but three of the deaths were in Hubei province, where the outbreak started.

The new figures, along with an upward revision of Hubei’s earlier count, brought the total number of cases in mainland China to 76,288, with 2,345 deaths. China has severely restricted travel and imposed strict quarantine measures to stop the virus from spreading.

A few Chinese provinces, eager to restart factories and their economies, began easing those restrictions after reporting no new cases in recent days. Liaoning and Gansu provinces both lowered their emergency response level, and two cities in Shaanxi province resumed bus services and removed checkpoints at railway stations, bus stations and on some highways.

Of the 229 new cases in South Korea, 200 are from Daegu and nearby areas. By Saturday morning, the city of 2.5 million and surrounding areas counted 352 cases, including two fatalities in the Cheongdo hospital. Both patients had pneumonia.

The central government has declared the area a “special management zone” and is channeling support to ease a shortage in hospital beds, medical personnel and equipment.

While some experts say the virus has started to spread nationwide, pointing to a number of infections in Seoul and elsewhere that weren’t immediately traceable, government officials remained hopeful of containing the outbreak.

“Although we are beginning to see some more cases nationwide, infections are still sporadic outside of the special management zone of Daegu and North Gyeongsang Province,” Kim said during a briefing. He called for maintaining strong border controls to prevent infections from China and elsewhere from entering South Korea.

Nationwide, the numbers told of a ballooning problem. There were 20 new cases reported Wednesday, 53 on Thursday and 100 on Friday.

Around 230 of those have been directly linked to a single house of worship, a Daegu branch of the Shincheonji Church of Jesus, where a woman in her 60s attended two services before testing positive for the virus.

Officials are also investigating a possible link between churchgoers and the spike in infections at the Cheongdo hospital, where more than 110 people have been infected so far, mostly patients at a mental illness ward.

Health officials were screening some 9,300 church followers, and said that 1,261 of them have exhibited cough and other symptoms.

Among them, four had traveled abroad in recent months, including one to China, although that trip came in early January and was not near Hubei.

All 74 sites operated by the Shincheonji Church have been closed and churchgoers 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 who first tested positive had contact with some 1,160 people, both at the church, a restaurant and a hospital where she was treated for injuries from a car accident.

But officials say it’s unlikely that the woman set off the chain of infections, and that she was probably just the first person to be detected in an area where the virus was circulating in the population.

Anxiety is also palpable in other parts of the country. In Seoul, South Korea’s capital, fear 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.

Rallies were banned in downtown Seoul, but hundreds went ahead with an anti-government protest on Saturday.

The first three cases in the country’s 600,000-member military also sprung up on separate bases Friday, bringing added concern. A U.S. Army garrison in Daegu restricted access and imposed self-quarantine for American troops.

“There remain zero confirmed cases of USFK personnel with COVID-19 despite the rise in confirmed South Korean cases,” U.S. Forces Korea said in a statement.

In Japan, new cases of the virus include a middle school teacher in her 60s, prompting concern for the health of other teachers and students in Makuhari in Chiba prefecture southeast of Tokyo.

Iranian health authorities on Saturday reported the country’s sixth death from the virus. The governor of Markazi province told the official IRNA news agency that tests of a patient who recently died was positive for the virus. Ali Aghazadeh said the person also had a heart problem. So far, 28 cases have been confirmed in Iran, including at least five of the six who died.

Saudi Arabia barred travel to Iran and said anyone coming from there can enter only after a 14-day quarantine. The decision directly impacts thousands of Iranians who travel to Mecca and Medina for Islamic pilgrimages, effectively barring them from the kingdom.

In the United States, 35 people have tested positive for the virus, including 18 who returned home from a quarantined cruise ship in Japan and one new case reported Friday in California.

Egypt is among 13 countries that the WHO identified as high priority in Africa because of direct travel links to China or a high volume of Chinese travel.

A growing number of African nations now have the laboratory ability to test for the virus, up from two early this month. About 11,000 health workers have been trained about the virus, Tedros said, and the WHO has shipped more than 30,000 sets of personal protective equipment to several African nations.