COVID-19 | Authorities in China introduced new Covid-19 curbs in areas surrounding Beijing on Tuesday, putting 4.9 million residents under lockdown as new infections raised worries about a second wave in a nation that has mostly contained the disease.

The number of new cases in mainland China reported on Tuesday almost halved from a day earlier and remain a small fraction of what it saw at the height of the outbreak in early 2020. However, local authorities are implementing strict curbs whenever new cases emerge to prevent the kind of economic paralysis seen a year ago...