State media said Saturday that only authorized vehicles to carry supplies and for other needs would be permitted.
Public transportation was shut down earlier this week, as well as flights and trains out of the city.
Authorities are trying to prevent the virus from spreading in the city and to other part of the country.
The English-language China Daily newspaper said that 6,000 taxis will be assigned to different neighborhoods to help people get around if they need to.
THIS IS A BREAKING NEWS UPDATE. The AP's previous story is below.
China's most festive holiday began in the shadow of a worrying new virus Saturday as the death toll surpassed 40, an unprecedented lockdown that kept people from traveling was expanded to more than 50 million residents and authorities canceled a host of Lunar New Year events.
The National Health Commission reported a jump in the number of infected people to 1,287 with 41 deaths. The latest tally comes from 29 provinces and cities across China and includes 237 patients in serious condition. All 41 deaths have been in China, including 39 in Hubei province, the epicenter of the outbreak, and one each in Hebei and Heilongjiang provinces.
Health authorities in the city of Hechi in Guangxi province said that a 2-year-old girl from Wuhan had been diagnosed with the illness after arriving in the city.
Australia announced its first case Saturday, a Chinese man in his 50s who last week returned from China. Malaysia said three people tested positive Friday, all relatives of a father and son from Wuhan who had been diagnosed with the virus earlier in neighboring Singapore.
France said that three people had fallen ill with the virus — the disease's first appearance in Europe. And the United States reported its second case, a Chicago woman in her 60s who was hospitalized in isolation after returning from China.
China added three cities to those cut off from transportation, bringing the total to 16 in Hubei province and covering a population greater than that of New York, London, Paris and Moscow combined.
Authorities are trying to limit further spread of the disease by preventing people from leaving Wuhan, the city of 11 million where the outbreak originated, and the surrounding area.
The Chinese military dispatched 450 medical staff, some with experience in past outbreaks including SARS and Ebola, who arrived in Wuhan late Friday night to help treat the many patients hospitalized with viral pneumonia, the official Xinhua News Agency reported.
The new virus comes from a large family of what are known as coronaviruses, some causing nothing worse than a cold. Symptoms include cough and fever and in more severe cases shortness of breath and pneumonia, which can be fatal.
SARS, which started in China in late 2002 and killed more than 750 people, was a coronavirus.
Stocks slumped Friday on Wall Street as economic fears grew over the widening crisis. The Dow Jones Industrial Average lost 170 points and the S&P 500 posted its worst day in three months. Shares in health care companies were down, along with those in financial institutions, airlines and other tourism and travel industry businesses.
It is not clear how lethal the new coronavirus is, or even whether it is as dangerous as the ordinary flu, which kills tens of thousands of people every year in the U.S. alone.
The rapid increase in reported deaths and illnesses does not necessarily mean the crisis is getting worse. It could instead reflect better monitoring and reporting of the newly discovered virus, which can cause cold- and flu-like symptoms, including cough, fever and shortness of breath, but can worsen to pneumonia.
The National Health Commission said Saturday that it is bringing in medical teams from outside Hubei to help handle the outbreak, a day after videos circulating online showed throngs of frantic people in masks lined up for examinations and complaints that family members had been turned away at hospitals that were at capacity.
The Ministry of Commerce is coordinating an effort to supply more than 2 million masks and other products from elsewhere in the country, Xinhua said.
Wuhan is throwing up a 1,000-bed prefab hospital to deal with the crisis, to be completed Feb. 3. It will be modeled on a SARS hospital that was built in Beijing in just six days during the 2003 SARS outbreak.
In France, Health Minister Agnes Buzyn said that two infected patients had traveled in China and that France should brace for more such cases. A third case was announced in a statement from her ministry about three hours later.
"We see how difficult it is in today's world to close the frontiers. In reality, it's not possible," she said. Buzyn said authorities are seeking to reach anyone who might have come in contact with the patients: "It's important to control the fire as quickly as possible."
In the U.S., the latest person confirmed to have the disease was reported to be doing well. The U.S. Centers for Disease Control and Prevention likewise said it is expecting more Americans to be diagnosed with the virus.
Still, "CDC believes that the immediate risk to the American public continues to be low at this time, but the situation continues to evolve rapidly," said the agency's Dr. Nancy Messonnier.
With Chinese authorities afraid that public gatherings will hasten the spread of the virus, the outbreak put a damper on Lunar New Year. Temples locked their doors, Beijing's Forbidden City, Shanghai Disneyland and other major tourist destinations closed, and people canceled restaurant reservations ahead of the holiday, normally a time of family reunions, sightseeing trips, fireworks displays and other festivities in the country of 1.4 billion people.
The vast majority of cases have been in and around Wuhan or involved people who visited the city or had personal connections to those infected. About two dozen cases in all have been confirmed outside mainland China, nearly all of them in Asia: Hong Kong, Macao, South Korea, Japan, Singapore, Thailand, Taiwan, Vietnam, Nepal, Australia and Malaysia.
While most of the deaths have been older patients, a 36-year-old man in Hubei died on Thursday.