Chinese authorities have introduced new Covid-19 curbs in areas surrounding Beijing, 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.

According to Reuters, the number of new cases in China reported almost halved from a day earlier and remained 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.

The city of Langfang in Hebei said its 4.9m residents will be put under home quarantine for seven days and be subject to mass Covid-19 testing.