Authorities in China's capital Beijing have closed about 40 subway stations over Covid-19 concerns, despite only recording about 50 daily infections.
China has been battling its worst coronavirus flare-up since the early days of the pandemic, with most cases found in the country's business capital of Shanghai.
On Wednesday, Beijing reported 51 local infections, of which five were asymptomatic. Shanghai reported about 5,000 cases as it eased some restrictions.
But new safety measures have been put in place to curb movement around the Chinese capital, with some residential compounds locked down after infections were reported.
Tourist sites also tightened rules for the busy May holiday this week and dining at restaurants was banned, AFP reported. People in Beijing have started to stock up on essentials over worries they could suddenly be told to stay at home.
China World Trade Centre, an office and shopping complex in Beijing, has been temporarily closed.
About 40 subway stations were closed on Wednesday, about 12 per cent of the network, the city's subway operator said. Many are near locked-down areas, the operator said on WeChat.
"The entrances and exits of stations will be closed ... but transfers can be done within the stations," it said.
"I think the city is already in a semi-closed state," one resident in a locked-down compound told AFP.
"There is no timetable for when our lockdown will be lifted, and more places are being sealed."
Another resident, 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, Chaoyang district, a heavily populated district in the capital, began another round of mass testing. The initiative is set to end on Thursday.
Covid testing in China's Xi'an and Beijing - in pictures
Elsewhere in China, the central city of Zhengzhou has increased Covid-19 restrictions, with residents in the city centre ordered to remain at home.
Authorities in Shanghai have struggled to deliver fresh vegetables and other essentials to people in lockdown and some patients say that have had trouble accessing non-Covid medical care.
Officials in the city have been criticised over their response to the rise in cases.
Hundreds have died from Covid-19 in Shanghai, many of them unvaccinated elderly people.
