BEIJING — More offices and stores in Beijing and other parts of China finally reopened Monday after the Lunar New Year break was extended to discourage travel and contain the new coronavirus, but many workers and shoppers appeared to stay home.

Public health authorities are watching closely to see whether the return to business worsens the spread of the virus, which has infected more than 40,000 people globally and killed over 900, with the vast majority of cases in China.

Even before the slow and cautious reopening, China on Monday reported a rise in new cases, dimming optimism that the near-quarantine of some 60 million people and other disease-control measures might be working.

Britain, meanwhile, declared the virus a “serious and imminent threat to public health” and said it would forcibly detain infected people if necessary. France tested scores of children and their parents after five British tourists contracted the virus at a ski resort.

The director-general of the World Health Organization said that the agency is still unable to predict where the outbreak is heading but that he believes there is still an opportunity to contain it.

The latest developments:

CHINESE OFFICES,

MARKETS START

TO REOPEN

Zhang Peng, who works for a livestreaming company in Beijing, went to the office for the first time since the holiday, which was supposed to end Jan. 30. The company checked employees for fever and handed out masks.

“I thought the situation is fairly good now,” Zhang said. “I went to work by subway today and underwent various checks in the station. And my company did a good job of prevention and control.”

Iris Ke, who works for an advertising company, said she plans to wait until next week to go back to the office.

“We just need to have a little more sense of self-protection,” said Ke. “Life goes on anyway. How come we stop going outside or stop working simply because of fear of disease? We can’t do that.”

There were few signs of activity on the streets of Beijing. The capital’s broad avenues were largely free of traffic, and thousands of rental bikes stood in long ranks with hardly a customer. Tourist attractions such as the Forbidden City remained closed, as did schools, and many people worked from home, hoping to avoid crowds.

Those shops and restaurants that did open found few customers.

The Beijing city government told residential compounds in the capital to close their gates, check visitors for fever and record their identities. The government also warned people to strictly abide by regulations requiring wearing of masks in public and to avoid group activities.

CHINA’S DEATH

TOLL RISES

The mainland death toll rose by 97 to 908 in the 24 hours through midnight Sunday, and 3,062 new cases were reported, government authorities said. That was up 15% from Saturday and broke a string of daily declines that the government had said showed that containment measures were succeeeding.

More than 440 cases have been confirmed outside mainland China, including two deaths in Hong Kong and the Philippines.

MORE CASES

ABOARD CRUISE SHIP

Japan said an additional 65 cases were found aboard a cruise ship quarantined in Yokohama, near Tokyo, raising the total to 135.

Health Minister Katsunobu Kato said the Japanese government was considering testing all 3,700 or so passengers and crew on the Diamond Princess, which would require them to remain aboard until results were available. Health authorities are scrambling to deliver medicine requested by more than 600 passengers.

INFLATION

Consumer inflation spiked to an eight-year high of 5.4% in January over a year earlier, driven by a 4.4% rise in food costs, the government reported.

“It appears that supply disruptions and hoarding due to the coronavirus outbreak helped to keep food prices elevated during the week after Chinese New Year, when they would normally drop back,” Julian Evans-Pritchard of Capital Economics said in a report.

China’s central bank announced a 300 billion yuan ($43 billion) fund to make low-interest loans to producers of medicine and medical supplies or other companies involved in fighting the virus.

Over the weekend, the government promised tax cuts and subsidies to farmers, supermarkets, producers of medical supplies and companies that contribute to anti-disease work.