Authorities have arrested three people in connection to a sewage tank collapse that killed 10 and left three severely injured in eastern China's Zhejiang Province.

The people's procuratorate of the city of Haining arrested Yu Bingliang, Huang Gaorong and Yu Huanhuan on suspicion of causing a major project safety accident.

The accident occurred in the Haining Longzhou Printing & Dyeing Co., Ltd. in early December. A sewage tank collapsed and crushed some factory floors. The wastewater flooded the factory and workers were trapped under falling debris.

Further investigation is underway.

China closed off a city of more than 11 million people Thursday in an unprecedented effort to try to contain a deadly new viral illness that has sickened hundreds and spread to other cities and countries in the Lunar New Year travel rush.

Normally bustling streets, shopping malls, restaurants and other public spaces in Wuhan were eerily quiet. Social media users posted that movie theaters were canceling showings and complained that food vendors were exploiting the situation with huge price increases on fresh produce.

Police, SWAT teams and paramilitary troops guarded the city's train station, where metal barriers blocked the entrances at 10 a.m. sharp. Only travelers holding tickets for the last trains were allowed to enter, with those booked for later trains being turned away. Virtually everyone at the scene was wearing masks, news website The Paper's live broadcast showed.

"To my knowledge, trying to contain a city of 11 million people is new to science," Gauden Galea, the World Health Organization's representative in China, told The Associated Press in an interview at the WHO's Beijing office. "It has not been tried before as a public health measure. We cannot at this stage say it will or it will not work."

Local authorities have demanded all residents wear masks in public places and urged government staff to wear them at work and for shopkeepers to post signs for their visitors, Xinhua news agency quoted a government notice as saying.

Train stations, the airport, subways, ferries and long-distance shuttle buses were stopped in the city, an industrial and transportation hub in central China's Hubei province. Xinhua cited the city's anti-virus task force as saying the measures were taken in an attempt to "effectively cut off the virus spread, resolutely curb the outbreak and guarantee the people's health and safety."

Cake Liu left Wuhan last Friday after visiting her boyfriend there. She said everything was normal then, before human-to-human transmission of the virus was confirmed. But things have changed rapidly.

"(My boyfriend) didn't sleep much yesterday. He disinfected his house and stocked up on instant noodles," Liu said. "He's not really going out. If he does he wears a mask."

The illnesses from a newly identified coronavirus first appeared last month in Wuhan, and the vast majority of mainland China's 571 cases have been in the city. Other cases have been reported in the Thailand, the United States, Japan and South Korea. One case was confirmed Thursday in Hong Kong after one was earlier confirmed in Macao. Most cases outside China were people from Wuhan or who had recently traveled there.

A total of 17 people have died, all of them in and around Wuhan. Their average age was 73, with the oldest 89 and the youngest 48.

The significant increase in illnesses reported just this week come as millions of Chinese travel for the Lunar New Year, one of the world's largest annual migrations of people. Analysts have predicted the reported cases will continue to multiply.

"Even if (the number of cases) are in the thousands, this would not surprise us," Galea said, adding, however, that the number of cases is not an indicator of the outbreak's severity, so long as the mortality rate remains low.

The coronavirus family includes the common cold as well as viruses that cause more serious illnesses, such as the SARS outbreak that spread from China to more than a dozen countries in 2002-2003 and killed about 800 people, and Middle Eastern respiratory syndrome, which developed from camels.

China is keen to avoid repeating mistakes with its handling of SARS. For months, even after the illness had spread around the world, China parked patients in hotels and drove them around in ambulances to conceal the true number of cases and avoid WHO experts.

In the current outbreak, China has been credited with sharing information rapidly, and President Xi Jinping has emphasized that as a priority.

"Party committees, governments and relevant departments at all levels must put people's lives and health first," he said Monday. "It is necessary to release epidemic information in a timely manner and deepen international cooperation."

The first cases in the Wuhan outbreak were connected to people who worked at or visited a seafood market, which has since been closed for an investigation. Experts suspect the virus was first transmitted from wild animals but the virus also may be mutating. Mutations can make it deadlier or more contagious.

WHO plans another meeting of scientific experts Thursday on whether to declare the outbreak a global health emergency, which it defines as an "extraordinary event" that constitutes a risk to other countries and requires a coordinated international response.

Many countries are screening travelers from China for illness, especially those arriving from Wuhan. North Korea has banned foreign tourists, a step it also took during the SARS outbreak and in recent years due to Ebola. Most foreigners going to North Korea are Chinese or travel there through neighboring China.

A Chinese city of more than 11 million people planned to shut down outbound flights and trains Thursday as the world's most populous country battled the spread of a new virus that has sickened hundreds of people and killed 17, state media reported.

Everyone in the city of Wuhan was to be restricted to some degree. The state-owned People's Daily newspaper said no one would be allowed to leave. The official Xinhua News Agency said no one would be permitted to leave without a specific reason.

Train stations and the airport were to shut down at 10 a.m. Buses, subways, ferries and long-distance shuttle buses would also be temporarily closed.

Most of the cases are in Wuhan and surrounding Hubei province, but dozens of infections have popped up this week around the country as millions travel for the Lunar New Year, one of the world's largest annual migrations of people. A handful of infected people who came from Wuhan have also been found overseas.

In Geneva, the World Health Organization put off deciding whether to declare the outbreak a global health emergency and asked an expert committee to continue meeting for a second day Thursday.

"We need more information," WHO Director-General Tedros Adhanom Ghebreyesus said.

WHO defines a global emergency as an "extraordinary event" that constitutes a risk to other countries and requires a coordinated international response.

When asked about Wuhan's public transport shutdown, WHO chief Tedros said authorities were likely acting to prevent transmission and mass gatherings.

"We cannot say they have done something unusual," he said.

The number of new cases has risen sharply in China, the center of the outbreak. The 17 deaths were all in Hubei province, where the outbreak emerged in the provincial capital of Wuhan late last month. Wuhan authorities said the province has confirmed 444 cases, which would bring the national total to more than 500.

The illness comes from a newly identified type of coronavirus, a family of viruses that can cause the common cold as well as more serious illnesses, such as the SARS outbreak that spread from China to more than a dozen countries in 2002-2003 and killed about 800 people. Some experts have drawn parallels between the new coronavirus and Middle Eastern respiratory syndrome, another coronavirus that does not spread easily among humans and is thought to be carried by camels.

"There has already been human-to-human transmission and infection of medical workers," Li Bin, deputy director of the National Health Commission, said at a news conference Wednesday. "Evidence has shown that the disease has been transmitted through the respiratory tract, and there is the possibility of viral mutation."

A tweet from WHO's Asia office this week raised the possibility that the epidemic is spreading more easily and may no longer require an animal source to spark infections, as officials initially reported.

Authorities in Thailand on Wednesday confirmed four cases — a Thai national and three Chinese visitors. Japan, South Korea, the United States, Taiwan and Macao, a former Portuguese colony that is a semi-autonomous Chinese city, have all reported one case each. All of the illnesses were of people from Wuhan or who recently traveled there.

"The situation is under control here," Thai Public Health Minister Anutin Charnvirakul told reporters, saying there are no reports of the infection spreading to others. "We checked all of them: taxi drivers, people who wheeled the wheelchairs for the patients, doctors and nurses who worked around them."

Dr. Peter Horby, a professor of emerging infectious diseases at Oxford University, said there were three criteria for the outbreak to be declared an international emergency: The outbreak must be an extraordinary event. There must be a risk of international spread, and a globally coordinated response is required.

"In my opinion, those three criteria have been met," he said.

In response to the U.S. case, President Donald Trump said: "We do have a plan, and we think it's going to be handled very well." He said the U.S. and China were both "in very good shape."

The patient, a man in his 30s who traveled to China in November, was doing well in an isolation unit in a hospital north of Seattle. He returned to Washington state Jan. 15, before the start of U.S. airport screening, health officials said.

In Wuhan, pharmacies limited sales of face masks to one package per customer as people lined up to buy them. Residents said they were not overly concerned as long as they took preventive measures.

"As an adult, I am not too worried about the disease," Yang Bin, the father of a 7-year-old, said after buying a mask. "I think we are more worried about our kids."

Medical workers in protective suits could be seen carrying supplies and stretchers into Wuhan Medical Treatment Center, where some of the patients are being treated.

Some countries have stepped up screening measures for travelers from China, especially those arriving from Wuhan. Travel agencies that organize trips to North Korea said the country banned foreign tourists because of the outbreak. Most tourists to North Korea are either Chinese or travel to the country through neighboring China.

Officials said it was too early to compare the new virus with SARS or MERS, or Middle East respiratory syndrome, in terms of how lethal it might be. They attributed the spike in new cases to improvements in detection and monitoring.

"We are still in the process of learning more about this disease," Gao Fu, an academician of the Chinese Academy of Sciences and head of the Chinese Center for Disease Control, said at the news conference.

Gao said officials are working on the assumption that the outbreak resulted from human exposure to wild animals being sold illegally at a food market in Wuhan and that the virus is mutating. Mutations can make it spread faster or make people sicker.

One veteran of the SARS outbreak said that while there are some similarities in the new virus — namely its origins in China and the link to animals — the current outbreak appears much milder.

Dr. David Heymann, who headed WHO's global response to SARS in 2003, said the new virus appears dangerous for older people with other health conditions, but doesn't seem nearly as infectious as SARS.

"It looks like it doesn't transmit through the air very easily and probably transmits through close contact," he said. "That was not the case with SARS."

Police in Thailand have arrested a man on suspicion of ruthlessly killing three people, including a toddler, during a gold shop robbery that shocked the country.

Local media said the suspect is the director of a primary school. It was unclear when he was arrested.

Thai TV stations on Wednesday broadcast live as police marched the man, wearing a face mask and baseball cap, into a police station in Lopburi, about 145 kilometers (90 miles) north of Bangkok, while a crowd of onlookers shouted abuse at him.

National police chief Chakthip Chaijinda said the suspect was cooperating and did not deny involvement.

The robbery took place Jan. 9 at a gold shop inside a shopping mall in Lopburi. Security video showed a man wearing a balaclava and camouflage pants approach the store, carrying a pistol with a long silencer attached.

He opened fire at staff and passersby. A 2-year-old boy was hit as he walked past with his mother. A security guard and a shop assistant were also killed. Four others were wounded.

The robber then jumped over the counter and grabbed a number of gold necklaces before fleeing.

The incident caused outrage in Thailand, putting authorities under pressure to make a swift arrest.

Police say they would give further details about the arrest at a news conference on Thursday.

Taiwanese President Tsai Ing-wen urged China on Wednesday to release all information about the outbreak of a new virus and work with Taiwan on curbing its spread.

At China's insistence, Taiwan is not a member of the World Health Organization and is not allowed to participate in any of its meetings. However, large numbers of Taiwanese travel to and live in China, where hundreds of people have been sickened and nine have died in an outbreak that apparently originated in the city of Wuhan.

Despite Beijing's restrictions, the Taiwan Center for Disease Control said earlier this month it had been notified on Jan. 15 by its Chinese counterpart about the outbreak. It said it had also sent two experts to Wuhan to visit health care facilities in order to "better understand the treatment process of the cases."

Tsai made no mention of those interactions at her news conference Wednesday.

"I especially want to urge China, being a member of international society, that it should fulfill its responsibilities to make the situation of the outbreak transparent, and to share accurate information on the outbreak with Taiwan," Tsai told reporters.

One case of the previously unknown coronavirus has been confirmed in Taiwan and others in Macao, South Korea, Japan, Thailand and the United States. The Taiwanese patient, a businesswoman who recently returned from Wuhan, is recovering, Tsai said.

Sharing information is also important for the health of the Chinese population and Beijing "should not put political concerns above the protection of its own people," Tsai said.

China regards Taiwan as its own territory and says it is not entitled to representation in most international bodies.

"I want to reiterate that Taiwan is a member of international society. The 23 million people here, like all other people in every corner of the world, are facing threats to their own health," Tsai said.

Taiwan, which was heavily affected by the 2002-2003 SARS outbreak that also originated in China, has enacted strict monitoring, detection and quarantine measures.

In Beijing, foreign ministry spokesman Geng Shuang said the Taiwanese experts had visited Wuhan at Taiwan's request on Jan. 13-14 and held exchanges with Chinese colleagues.

"No one cares more about the health welfare of Taiwan compatriots than the Chinese central government," Geng said at a daily briefing on Wednesday.