(CNN) – Millions of Shanghai residents braved sweltering heat Tuesday to wait in line for compulsory Covid tests, as growing case numbers and the emergence of a highly infectious Omicron subvariant spurred new fears of a return to mass lockdown.
Shanghai authorities have ordered the majority of the city’s 16 districts to undergo two rounds of testing from Tuesday to Thursday, after a case of the new BA.5.2.1 subvariant was detected in the community on July 8.
The highly transmissible BA.5 variant is spreading rapidly worldwide and is seen as a great threat by authorities in China — the last major country adhering to a stringent zero-Covid strategy.
New Omicron subvariants have been reported in several Chinese cities, including the capital Beijing, the northeastern port city of Dalian, and the central city of Xi’an, which was shut down for seven days over the outbreak.
The rising cases — and accompanying restrictions — come as a scorching heatwave sweeps the country. In Shanghai, authorities raised the highest-level red alert Sunday as temperatures hit 40 degrees Celsius (104 Fahrenheit).
The stifling heat has made mass testing all the more excruciating for residents — some of whom have to queue for hours — and for Covid workers, who are covered head to toe in airtight PPE equipment.
On Chinese social media, photos went viral of workers in hazmat suits lying on ice blocks, while health experts warned of heatstroke among Covid workers who spend long hours outdoors in thick protective clothing.
Shanghai saw a jump in infections earlier this month, due to an outbreak linked to a karaoke bar. Over the past 10 days, it has reported more than 400 cases.
The growing outbreak has fueled fears the commercial hub is headed back into a mass lockdown, just weeks after its residents emerged from two months of grueling home confinement.
The city of 25 million ended its citywide lockdown at the start of June, but has continued to impose tough restrictions, including relentless testing and snap lockdowns on compounds where Covid cases were found.
As of Tuesday, 240 neighborhoods across Shanghai have been marked as medium- or high-risk areas and placed under lockdown.
Shanghai officials have repeatedly denied that a citywide lockdown is imminent, but that has failed to convince residents, who noted that authorities had also made similar claims in March in the lead up to the previous lockdown.
On Monday, two neighborhood committees in Shanghai said residents should “prepare food and medicines that can last for 14 days at home, to be on the safe side.”
The notices, after being widely circulated online, caused panic among residents, many of whom are scarred by their prolonged isolation in April and May — which led to widespread food shortages and blocked access to medical care.
In response to the uproar, a neighborhood committee worker told the state-run Health Times the proposal was meant to prepare residents for the growing outbreak, as close contacts — as well as secondary contacts — of an infected case can also lead to neighborhood lockdowns.
“Fine, let’s spend our whole life living in the fear of food scarcity and the shadow of hoarding daily necessities,” said a comment on Weibo, China’s Twitter-like platform.
“It’s been over three years, when will it be over? How many three years do people have in their lives? Enough is enough!” said another.