The major port of Tianjin may be facing China’s first local outbreak of the Omicron variant of coronavirus of any size, less than a month before the winter Olympics open in nearby Beijing.
State broadcaster CCTV said the government has divided Tianjin and its 14 million residents into three levels of restrictions, starting with lockdown areas where people are not allowed to leave their homes at all.
In control areas, each household is allowed to have one family member leave to buy groceries every other day, while in prevention areas, people must remain inside their immediate neighbourhoods.
Buses and trains from Tianjin to Beijing have been suspended and people are being told not to leave the city unless they have urgent business.
The city began mass testing of all its residents on Sunday after a cluster of 20 children and adults tested positive for Covid-19, including at least two with the Omicron variant.
Another 20 people tested positive on Sunday, bringing the total to 40. Officials said earlier that the virus has been circulating so the number of cases could rise.
China has stepped up its strict zero tolerance strategy in the run-up to the Olympics, which open on February 4.
The Chinese capital is 70 miles northwest of Tianjin and many people regularly travel back and forth by car or on a high-speed rail link that takes less than one hour.
Elsewhere, millions of people are being confined to their homes in Xi’an and Yuzhou, two cities that are further away but have larger outbreaks traced to the Delta variant.
Residents of Xi’an have been under lockdown for more than two weeks, but the number of new cases in the city of 13 million fell to just 15 on Monday in a sign that restrictions could soon be lifted.
Yuzhou is a city of about 1.1 million people in neighbouring Henan province.
Another 60 cases were reported on Monday in Henan, two of them of the Omicron variant, state media outlet The Paper reported.
The provincial capital of Zhengzhou has been conducting mass testing and closed its schools. Another 24 cases were reported in the city on Monday.
China had reported about a dozen Omicron cases previously, most among people who had arrived from abroad and were isolated.
