Millions of people in areas surrounding China's capital were ordered into lockdown, with authorities doubling down on efforts to contain Covid-19 ahead of a key ruling Communist Party meeting this year.
Nearly four million people in Hebei province, which surrounds Beijing, were ordered to stay home until the end of the week as officials rush to curb a small virus flare-up.
And more than 13 million in the neighbouring port city of Tianjin must undergo mass testing, after 51 mostly mild cases were reported.
China is the only major global economy sticking to a zero-Covid policy, and lockdowns, travel restrictions and mass testing have disrupted businesses and cooled growth.