Beijing closed dozens of subway stations on Wednesday as Covid restrictions constrict movement around the Chinese capital despite it recording only dozens of cases daily.
China has been battling its worst coronavirus flare-up since the early days of the pandemic, with most cases found in the business hub of Shanghai.
Scenes of chaos and anger at weeks of stay-at-home orders in Shanghai have alarmed people in the capital who fear their city may be next.
On Wednesday Beijing reported just 51 local infections, five of them asymptomatic, while Shanghai reported nearly 5,000 -- part of a downward trend as Shanghai loosens some restrictions.
Some Beijing housing compounds where infections have been reported have already been locked down, while many tourist sites tightened rules for the busy May holiday this week. Dining-in at restaurants has also been banned.
Beijingers have started stocking up on essentials over worries they could suddenly be ordered to stay at home.
The China World Trade Center -- an office and shopping complex -- has been temporarily closed this week.
The city's subway operator announced the closure of about 40 stations Wednesday -- around 12 percent of the network -- many of them near locked down areas, according to an announcement on its WeChat page.
"The entrances and exits of stations will be closed... but transfers can be done within the stations," the notice said.
"I think the city is already in a semi-closed state," said one Beijing resident in a sealed compound who declined to be identified.
"There is no timetable for when our lockdown will be lifted, and more places are being sealed," he told AFP, saying freedoms were increasingly being limited.
Another Beijinger, aged 35, said he was buying groceries online to avoid contact with people at supermarkets.
"No one can really tell how long the restrictions will last... but I understand the reasoning," he said.
On Tuesday Beijing's heavily populated Chaoyang district started another round of mass testing, set to end on Thursday.
Elsewhere in China, the central city of Zhengzhou has also ramped up Covid controls, with residents in the city centre ordered to remain in their housing compounds or at home.
Authorities in Shanghai have struggled to get fresh vegetables and other essentials to people in lockdown and patients have reported trouble accessing non-Covid medical care.
Local officials have been accused of bungling their response to the virus and being overzealous with the implementation of restrictions.
Hundreds have died with Covid in Shanghai, many of them unvaccinated elderly people.