Shanghai and other big Chinese cities, including Shenzhen, have ramped up testing for COVID-19 as infections rise, with some local authorities hastily closing schools, entertainment venues and tourist spots.
Infections have risen to the highest since August, with the uptick coming after increased domestic travel during the National Day "Golden Week" earlier this month.
Authorities reported 2,089 new local infections for Oct. 10, the most since Aug. 20.
While many of the cases were found in tourist destinations, including scenic spots in the northern region of Inner Mongolia, megacities that are often the source of well-travelled tourists have started to report more cases this week.
Shanghai, a city of 25 million people, reported 28 local cases for Oct. 10, the fourth day of double-digit increases.
Keen to avoid a reprise of the economically and psychically scarring lockdown in April-May, Shanghai said late on Monday that all its 16 districts were to conduct mass testing at least twice a week until Nov. 10, a step up from once a week under a regime imposed after the last lockdown.
Checks on inbound travellers and in places such as hotels should also be strengthened, authorities said.
The expanding web of measures have already ensnared some.
Peter Lee, a long-time British expatriate, was out at lunch with his wife and seven-year-old son last week when he was notified his apartment block was to be locked down.
Lee and his son then checked into a hotel, which was soon also locked down, due to a prior visit by a virus carrier. Lee's wife, who was planning to join them, had no choice but returned home to be locked in.
"It might be that we say, we miss home and we miss mum too much and maybe we just go home and just deal with it," Lee told Reuters.
"We're monitoring the situation because it seems like Shanghai is gradually shutting down anyway and if everything starts to close then there won't be much benefit in being able to come and go."
As of Monday, 36 Chinese cities were under various degrees of lockdown or control, affecting around 196.9 million people, versus 179.7 million in the previous week, according to Nomura.
In China's southern tech hub Shenzhen, where the highly transmissible BF.7 Omicron subvariant has surfaced, local cases more than tripled to 33 on Oct. 10 from a day earlier.
Inbound travellers will be subject to three tests over three days, authorities in the city of 18 million people said on Tuesday.
In the northwestern city of Xian, which reported just over 100 cases from Oct. 1-10, authorities halted offline classes at schools and closed many public spaces including the famous Terracotta Warriors Museum.
Daily shuttle buses ferrying tens of thousands of people to work in Beijing from nearby Tianjin and Hebei will be suspended from Wednesday due to the COVID resurgence.
Despite China's very small caseload versus the rest of the world, and the toll its counter-epidemic policies exact on the economy and population, the government has repeatedly urged people to accept the measures.
"Once a large-scale rebound occurs, the epidemic will spread, and is bound to have a serious impact on economic and social development, and the final price will be higher and losses will be greater," state-controlled People's Daily wrote in a commentary on Tuesday.
The COVID preventive steps come days ahead of a Communist Party congress starting on Oct. 16 where Xi Jinping is expected to extend his leadership.
"The latest resurgence of draconian COVID-19 restrictions is likely to be temporary given the priority to keep things under control ahead of the all-important meeting," said analysts from U.S. alternative asset management firm Clocktower Group.
"However, the People's Daily's tripling down on the zero-COVID-19 narrative is indeed a major concern, which suggest that a major policy recalibration may still be far away."