BEIJING, China -- Multiple Chinese cities have cancelled routine mass Covid tests this week, days after Beijing announced limited relaxations of its strict zero-Covid policy which raised hopes of China's eventual reopening.

The National Health Commission (NHC) on Friday issued 20 rules for "optimising" zero-Covid, where certain restrictions were relaxed to limit its social and economic impact.

China reported over 20,000 new infections Wednesday -- the highest figure since April -- with major outbreaks in the cities of Guangzhou and Chongqing.

Routine mass PCR testing is one of the key tools used to trace outbreaks, with cities such as Beijing and Shanghai requiring residents to show 72-hour test results to enter public spaces and use public transport.

But many complain that it wastes time and long queues increase transmission risk, while operating free testing services has heavily strained local government budgets.

Shanghai abolished mandatory mass testing by city district on Sunday, China News Service reported citing anonymous local officials.

However, officials caveated that it will "only be carried out when the source of infection and transmission chain are unclear, and it has been spreading in the community for a long time", echoing language from the NHC announcement.

Shijiazhuang, a city of 11 million in northern Hebei province, also vowed Sunday to implement the 20 measures in an open letter to residents.

China Newsweek reported that routine mass testing had been cancelled, except for "key groups", citing local officials.

Residents would still require a 72-hour test result to use public transport and to access key sites such as hotels, according to local media reports.

Shijiazhuang's Communist Party boss reiterated Monday that the new measures were neither "lying flat" or a "full relaxation", after the Weibo hashtag "Shijiazhuang epidemic prevention" went viral.

Social media users reacted with celebration but also alarm, with many complaining Wednesday that parcels could not be sent from the city due to strict virus controls by other local governments.

"I'm speechless, why doesn't the whole country open up instead of using Shijiazhuang as an experimental site?" one local resident wrote on Weibo.

"We cannot travel elsewhere and parcels don't get delivered here, I can't leave the city to take an exam, it's disgusting."

Other cities including Yanji in northeastern Jilin province and Hefei in eastern Anhui province also cancelled routine mass testing earlier this week.

The new rules say the "scope of nucleic acid testing shall not be expanded" and that mass testing will not be conducted in areas without outbreaks except for "key personnel and sites of employment".

The measures also urged local governments to "correct unscientific practices such as two or three tests per day".

The city of Ghulja in the northwestern region of Xinjiang will resume normal life and work Wednesday, local authorities announced, lifting a harsh three-month lockdown plagued by food shortages.