Beijing launched a campaign to test two million people in 48 hours as the city rushes to eradicate a new local cluster of COVID-19 cases that could be linked to a more infectious variant of the virus, AFP reported.
Officials plan to complete testing by Saturday.
Beijing is rushing to test as China has the highest number of cases almost a year after the COVID-19 was first detected in the central city of Wuhan in late 2019.
Officials said some of the cases identified in Beijing are linked to a variant of the deadly pathogen that was first discovered in the UK and is considered more infectious.
China reported 103 new cases of Covid-19 on Friday, including six in Shanghai and three in Beijing.