Chinese authorities have stepped up Covid lockdowns and other curbs to contain outbreaks as the number of cases soared to its highest since millions of people were confined to their homes this year, with Beijing and Zhengzhou seeing record tallies.

Authorities reported 10,535 new domestically transmitted cases for yesterday, the highest number since 29 April, when the commercial hub of Shanghai, was battling its most serious outbreak under strict lockdown.

The nationwide surge, still small by global standards and for a country of 1.4 billion people, has spurred the top leadership to reaffirm its zero-tolerance strategy for the virus, a policy that President Xi Jinping says is to save lives, especially among the elderly.

The southern city of Guangzhou - the new epicentre of China's Covid fight - reported 2,824 new local cases for 10 November, the fourth day in which infections exceeded 2,000.

Driving the infections were cases in the populous Haizhu district, which today extended a lockdown until Sunday. At least three of Guangzhou's 11 districts have been put under varying levels of restrictions.

"All residents are required to stay at home," the district government said in a statement. "Only one person in each household is allowed to buy daily necessities on a staggered schedule."

All public transit in the district of 1.8 million people has been suspended, and mandatory PCR tests will be administered to "every household and every individual", the district government said.

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China will not relax its Covid measures but will keep improving them according to the changing situation and mutation of the virus, a government expert was cited as saying by the national health authority.

Beijing, Zhengzhou and Chongqing also tightened measures as daily cases rose to around all-time highs.

Zhengzhou, capital of central Henan province, reported 2,988 new cases, more than double from a day earlier, in a widening outbreak that has thrown an iPhone assembly plant of Apple supplier Foxconn into chaos.

In the southwestern metropolis of Chongqing, cases remained in the triple digits all week, with a new high of 783 yesterday.

Some districts have banned dining at restaurants and some subway stations were closed.

Beijing reported a record 118 new domestic cases, which is still low compared with other Chinese cities.

People queue for routine Covid tests in Yichang, Hubei province

Authorities in many parts of the city of nearly 22 million people have urged residents to take PCR tests every day, or be barred entry to public spaces including offices, leisure venues and fitness centres.

Sanya, a beach resort city in the southern island province of Hainan, said it would launch a round of mass testing tomorrow.

Chinese shares rose following US CPI data and some bets on more pragmatic Chinese measures to contain the Covid outbreaks,but tourism stocks sank more than 2%.

The new top leadership body of the ruling Communist Party yesterday reaffirmed the zero-Covid policy, saying measures should not be relaxed, with state media reporting that "20 measures" would be further improved, without elaborating.

The Politburo Standing Committee stressed the need to minimise the impact of containment measures on the economy.

Strategies that oversimplify measures, as well as one-size-fits-all policies.

Meanwhile, China announced the relaxation of some of its hardline Covid-19 restrictions, cutting the quarantine period for inbound travellers from ten days to eight and scrapping snap closures of flight routes.

The National Health Commission also said it was abolishing the requirement to identify and isolate "secondary close contacts".

In a notice published on state-run CCTV, the government said the powerful seven-man Politburo Standing Committee met yesterday to rubberstamp the limited relaxations.

Inbound arrivals will still be required to undergo six nucleic acid tests and will not be allowed to freely set foot outside during those eight days, the notice said.

It added that travellers will only be required to show one negative Covid test within 48 hours of boarding flights to China, a reduction from the current two tests.

The new rules single out "important business personnel" and "sports groups" as examples of privileged groups permitted to skip quarantine as long as they remain in a virus-secure "closed loop" for the duration of their stays.

A so-called "circuit breaker" mechanism on inbound flights would be abolished, the notice added, bringing an end to a policy that saw the snap closures of flight routes if a certain proportion of passengers tested positive for the virus.