Beijing is imposing further control measures in an attempt to prevent a new outbreak in the capital from spreading to other parts of the country.
In addition to locking down communities and ordering mass testing of thousands of people, China's capital is banning residents of areas considered at high risk from leaving the city, according to health authorities. Those from such areas who have already left must report to local health bureaus as soon as possible.
The number of passengers on buses, trains and subways will also be limited and all will be required to wear masks.
Authorities confirmed 106 cases since Friday in what looks to be the largest outbreak since China largely stopped its spread at home more than two months ago.
The resurgence of infections gives a bleak insight into the challenges ahead for European countries just as they reopen their borders.
The head of the World Health Organization said more than 100,000 confirmed cases of coronavirus have been reported globally each day in the last two weeks, and countries that have curbed transmissions ``"must stay alert to the possibility of resurgence."
Tedros Adhanom Ghebreyesus noted that it took over two months to reach 100,000 reported cases, now a daily norm. Each day, nearly three-fourths of the new cases come from 10 countries, mostly in South Asia and the Americas, he said.
Stock markets fell in Paris, London, Tokyo and Shanghai on Monday on fears of a second wave of COVID-19. Infections are still rising in a number of countries, and without a vaccine, there is a risk that relaxing lockdowns and travel restrictions could spark a rebound in cases.
China’s new outbreak appears to have started in the Xinfadi market, Beijing's largest wholesale food market.
Beijing has closed the market and is requiring anyone who went there to self-isolate for two weeks.
Citywide, Beijing has suspended the planned reopening on Monday of some primary schools and reversed the relaxation of some social isolation measures.
Inspectors found 40 samples of the virus in the closed market, including on a chopping board for imported salmon.
Beijing health officials said gene sequencing showed the virus strain causing the new outbreak was related to that in Europe, though it wasn't clear if it was being spread by the movement of people or transportation of food.
Nearly 8 million cases of COVID-19 have been confirmed worldwide as of June 15, and more than 433,000 people have died from the disease, according to a tally by Johns Hopkins University.
Several countries are still battling major outbreaks.
India's Health Ministry reported a jump of more than 11,000 new infections nationwide for a third consecutive day on Monday. The country's home minister offered 500 train carriages for use as makeshift coronavirus hospital wards as New Delhi struggles to contain a spike in cases.
In the United States, cases in nearly half of states are rising. New York Governor Andrew Cuomo threatened to reinstate closings in areas where local governments fail to enforce social distancing rules.
“We are not kidding around with this,” Cuomo said at his daily briefing on Sunday. “You're talking about jeopardising people's lives.''
In the UK, non-essential stores are preparing to welcome back shoppers this week. On Sunday, Prime Minister Boris Johnson stopped for coffee at one London mall, where he urged people to "shop with confidence" but to follow the COVID-19 safety measures while doing so.
In France, restaurants in the Paris region are now allowed to join those in the rest of the country in reopening indoor seating. From June 22, all nursery schools, primary schools and junior high schools will be open and mandatory for all students.