WUHAN, China — The repercussions from a mysterious virus that has sickened hundreds of people began reverberating far from its epicenter in central China on Saturday, as Hong Kong closed its schools for several weeks, Beijing began restricting buses in and out of the capital, and the country’s travel association suspended Chinese tour groups heading overseas.
The new measures, coming on top of previous travel restrictions that had effectively penned in tens of millions of people in Hubei, the province at the heart of the outbreak, are certain to further dampen celebrations of the Lunar New Year, which began on Saturday.
They came, too, as China’s top leader, Xi Jinping, who had said little publicly about the crisis despite growing criticism of the response, pledged Saturday that officials would “stand at the front line to safeguard social stability.”
The illness linked to the virus has killed at least 56 people and sickened more than 1,300 in China, according to official reports. Cases have been confirmed in all but one of China’s provinces and autonomous regions, as well as in at least 11 other countries as the virus has spread to Europe, the United States Australia and, most recently, Canada.
Among the newest victims in China was a 62-year-old ear, nose and throat specialist, who died on Saturday, according to state news media. It was unclear whether the doctor, who had retired last year, had treated patients with the disease.
And officials in the southern city of Hechi said on Saturday that a 2-year-old girl suffering from the coronavirus had been admitted to a hospital, becoming the youngest person known to be infected.
In a sign of how the coronavirus has shaken China, Mr. Xi convened a meeting of Communist Party leaders on Saturday to try to stem the outbreak.
“We’re sure to be able to win in this battle to beat the epidemic,” said Mr. Xi, according to a summary of his remarks by state media, offering some of his most extensive remarks to date on the crisis.
Mr. Xi called for stronger efforts to provide medicine and other supplies to affected areas. Shortages have angered doctors and medical workers, particularly in Wuhan, the Hubei provincial capital where the outbreak began. Hospitals have issued pleas for donated supplies.
Party leaders also directed railway stations, airports and ports to step up measures to deter the spread of the virus, through ventilation, disinfection and body temperature checks.
Chinese officials announced later Saturday that more than 1,200 medical personnel would be sent to Wuhan and over 10,000 beds in 24 local hospitals would be requisitioned for treating confirmed and suspected cases of the virus.
But the official response so far has drawn stinging rebukes on social media, where people are questioning whether the authorities are accurately reporting the number of cases or doing enough to rein in the outbreak. In particular, people have denounced the perceived indifference of local, provincial and even national authorities.
“Where is that person? He is not on the front line,” one user wrote on Weibo, a Twitter-like platform, in an apparent reference to Mr. Xi.
State media has maintained a steady drumbeat of positive news about the outbreak, praising the sacrifices of responders and everyday people. But there was little doubt the disease had derailed celebrations of the Lunar New Year, the country’s biggest holiday and busiest travel period.
Travel constraints imposed earlier in Wuhan and 12 nearby cities have effectively penned in 35 million people. Wuhan tightened its restrictions further on Saturday, with a ban on most vehicle traffic in the city center.
The restrictions began spreading far beyond Wuhan, too: In Beijing, the city government said it would halt all inter-province buses beginning on Sunday, effectively limiting road travel into the capital.
The association of China’s travel agencies said that it would suspend all tour groups and the sale of flight and hotel packages for citizens headed overseas, starting on Monday. Groups already on their trips were allowed to continue, with the directive that travelers’ health be closely monitored.
The move to cut off group tours could have a ripple effect across countries that depend on Chinese tourists. While China is now home to an increasingly sophisticated population ready to hit the tourist routes by themselves, a large number of Chinese do not feel comfortable traveling abroad unless they are with a group.
New measures were also imposed in Hong Kong, where its leader, Carrie Lam, declared a health emergency. Five coronavirus patients connected to Wuhan are being treated in Hong Kong, and more than 100 others are suspected of having the viral pneumonia.
Lunar New Year celebrations are being canceled in Hong Kong, schools will be closed until mid-February and the Hong Kong Marathon has been called off. The city is also suspending flights and train services to Wuhan.
A study by the medical journal The Lancet, published on Friday, raised new concerns that people infected with the coronavirus might be able to spread it even if they do not have flu-like symptoms.
Researchers studied a family in the Chinese city of Shenzhen, five of whom had traveled to Wuhan and two of whom had come in contact with an infected relative in a hospital there. Testing conducted after the family flew home found that six members had the coronavirus, including one who had not gone to Wuhan.
One infected family member, a child, had no symptoms, suggesting that people with the virus might be spreading it without knowing that they have it, the study found.
“It shows this new coronavirus is able to transfer between person to person, in a hospital setting, a family home setting, and also in an intercity setting,” Yuen Kwok-yung, an author of the study, said in an interview. “This is exactly what makes this new disease difficult to control.”
The United States Embassy said on Saturday that all American employees at its consulate in Wuhan have been ordered to leave. The United States government is arranging a charter flight to evacuate American diplomats and citizens on Sunday, according to a person familiar with the plan.
For people in the United States with close ties to China, the outbreak has brought worry, disappointment and scrutiny. Some Chinese-Americans have had their Lunar New Year plans waylaid, as travel schedules for the coming week and beyond are interrupted.
Chinese-Americans have scrambled, though, to send aid to their friends and family in China.
Sean Shi, of Issaquah, Wash., said he shipped several boxes of masks to China in a friend’s luggage, hoping that they could reach friends in the Wuhan area. Later in the day, Mr. Shi was back at a hardware store, buying another 46 masks for some of his former peers at Wuhan University.
“We understand it’s a tough situation over there — the panic, the shortage of equipment,” Mr. Shi said. “We just realized the situation is very serious — more serious than we thought.”
Christopher Buckley reported from Wuhan, and Tiffany May from Hong Kong. Reporting was contributed by Steven Lee Myers, Vivian Wang, Raymond Zhong, Carlos Tejada, Rick Gladstone, Mike Baker, Jeffrey E. Singer and Elian Peltier. Yiwei Wang and Claire Fu contributed research.