Half a million people in a single Chinese city are being infected with COVID-19 every day, a senior health official has said, in a rare and quickly censored acknowledgement that the country's wave of infections is not being reflected in official statistics.

China this month has rapidly dismantled key pillars of its zero-COVID strategy, doing away with snap lockdowns, lengthy quarantines and travel curbs in a jarring reversal of its hallmark containment strategy.

Cities across the country have struggled to cope as surging infections have emptied pharmacy shelves, filled hospital wards and appeared to cause backlogs at crematoriums and funeral homes.

But the end of strict testing mandates has made caseloads virtually impossible to track, while authorities have narrowed the medical definition of a COVID death in a move experts have said will suppress the number of fatalities attributable to the virus.

A news outlet operated by the ruling Communist Party in Qingdao on Friday reported the municipal health chief as saying that the eastern city was seeing "between 490,000 and 530,000" new COVID cases a day.

The coastal city of around 10 million people was "in a period of rapid transmission ahead of an approaching peak", Bo Tao reportedly said, adding that the infection rate would accelerate by another 10 per cent over the weekend.

The report was shared by several other news outlets but appeared to have been edited by Saturday morning to remove the case figures.

China's National Health Commission said Saturday that 4,103 new domestic infections were recorded nationwide the previous day, with no new deaths.

In Shandong, the province where Qingdao is located, authorities officially logged just 31 new domestic cases.

China's government keeps a tight leash on the country's media, with legions of online censors on hand to scrub out content deemed politically sensitive.

Most government-run publications have downplayed the severity of the country's exit wave, instead depicting the policy reversal as logical and controlled.

But some outlets have hinted at shortages of medicine and hospitals under strain, though estimates of actual case numbers remain rare.

The government of eastern Jiangxi province said in a Friday social media post that 80 per cent of its population -- equivalent to around 36 million people -- would be infected by March.

More than 18,000 COVID patients had been admitted to major medical institutions in the province in the two weeks up to Thursday, including nearly 500 severe cases but no deaths, the statement said.

Dramatic shift in policy 

China's sudden decision to reverse its zero-COVID strategy came right after rare protests broke out in Shanghai and Beijing last month. 

The policy reversal appears to have caught many departments by surprise, with Beijing groping for a coherent narrative to explain the decision. 

For years, the country's propaganda apparatus hailed zero-COVID as proof of the superiority of the Communist Party's authoritarian rule and the wisdom of powerful President Xi Jinping.

But now its usual mouthpieces have been left to spin the decision to scrap strict travel curbs, quarantines and snap lockdowns as a victory even as cases soar.

"State media has not come up with a grand narrative to fully legitimise the sudden and radical change," said Kecheng Fang, an assistant professor at the Chinese University of Hong Kong's School of Journalism and Communication.

"They were caught by surprise."

The "inconsistent messaging" indicated that the propaganda apparatus may lack adequate directives from the party on how to frame the situation, he told AFP.

'A stirring battle'

Some outlets have hinted that not all is well, with state news agency Xinhua and state broadcaster CCTV this week running reports urging people to use COVID medicines "rationally" and highlighting government efforts to guarantee supply.

But government-run publications have refrained from reporting the grimmer side of the exit wave, instead seeking to calm fears of the pathogen's potency and depicting the policy shift as a logical, controlled and triumphant withdrawal.

"Looking back on the last three years, we have waged a stirring battle against the pandemic and gone through an arduous historical test," read an editorial in the party-run People's Daily newspaper last week.

Zero-COVID "demonstrated the superiority of China's socialist system", it said, adding that "optimising" the policy now would help to adapt to new virus variants while "putting the lives and health of the people and masses first".

There has also been a reluctance to address the mounting COVID caseload.

On Friday, a party-run newspaper cited an official estimate of half a million daily new cases in the eastern city of Qingdao. By Saturday, the story had been amended to remove the figure, an AFP review of the article showed.

And while Xi's recent flurry of diplomatic engagements has dominated the headlines, he has not yet commented publicly on the collapse of what was until recently a signature policy.

'Severe cold'

A similar sense of uncertainty has pervaded Chinese social media, where censors routinely scrub out politically sensitive content.

Several posts on the popular Weibo platform purporting to describe COVID-related deaths appeared to have been censored by Friday afternoon, according to a review by AFP journalists.

They included several blanked-out photos ostensibly taken at crematoriums, and a post from an account claiming to belong to the mother of a two-year-old girl who died after contracting the virus.

Posts about medicine shortages and instances of price gouging were also taken down, according to censorship monitor GreatFire.org.

And social media users have posted angry or sardonic comments in response to the perceived taboo around COVID deaths.

Many rounded on a state-linked local news outlet after it reported Wu Guanying -- designer of the mascots for the 2008 Beijing Olympics -- had died of a "severe cold" at the age of 67.

One commenter likened the phrasing to China's dictatorial neighbour North Korea, while another asked: "Is it illegal to say 'COVID' now?"

Yet other critical posts remained online as of Friday afternoon -- including many that took the government to task for its perceived lack of an exit strategy.

"Did they really believe they could wipe out the virus with lockdowns?" read one.

"Three years, and they never made a contingency plan for when it couldn't be controlled?"

Fang, the assistant professor, said Chinese officials would "eventually find a way to frame everything as a victory, maybe after the infection situation stabilises".

"The unique way of counting COVID deaths is already providing a basis for that," he added -- referencing a new government definition of virus deaths that excludes many fatalities.

China on Saturday officially recorded no new deaths from the virus, according to figures from the National Health Commission.

A Weibo hashtag relating to how the country defines COVID deaths -- counting only those who die from respiratory failure after testing positive -- was censored.