Controls could get even tighter, reports Asia Editor Debi Edward
Local authorities in Shanghai have fenced off apartment buildings to restrict the population's movement as case numbers continue to rise. Barriers have been set up outside buildings preventing residents inside from leaving.
Streets have been left deserted.
Videos captured by ITV News shows fences that forbid residents from leaving their homes.
The strict tactics employed by Shanghai officials come as Covid case numbers in Beijing climbed over the weekend.
So far, 70 cases have been found in the city of more than 21 million since the outbreak surfaced Friday
The new statistics have prompted authorities in the capital to lockdown communities which have been hit by the virus.
Millions of residents are currently being tested and authorities have begun shutting down residential and business districts on Monday amid a new outbreak of Covid-19
Residents were staying home and stocking up on food as a safeguard against the possibility that they could be confined indoors, as has happened in multiple cities, including the financial hub of Shanghai.
Having seen what has gone on in Shanghai, as it's 25-million strong population have been shut in their homes for weeks, Beijing residents are stocking up on food and essentials as fears of a lockdown grow.
Long lines formed in supermarkets in central Beijing. Shoppers snapped up rice, noodles, vegetables and other food items while store workers hastily restocked some empty shelves.
State media issued reports saying supplies remained plentiful in Beijing despite the buying surge.
Lockdowns implemented by the Chinese government to crackdown on Covid cases have led to panic buying, shortages of food and medical services as well as growing public anger.
China has stuck to its “zero-Covid” strategy of handling outbreaks with strict isolation and mass testing.
China's government and state-controlled media have remained defensive about complaints over the Covid prevention measures.
Mounting concerns have also been voiced over the effect the lockdown will have on the economy in China's largest city.
Beijing health officials said 29 more cases had been identified in the 24 hours through 4 p.m. Monday, raising the total to at least 70 since Friday.
The city has ordered mass testing across the sprawling Chaoyang district, where 46 cases have been identified.
More than three million residents of Chaoyang and people who work in the district are required to be tested on Monday, Wednesday, and Friday.
Testing sites were set up overnight and in the early morning at Chaoyang district's residential complexes and office buildings.
"I think Beijing should be fine," said Gao Haiyang as he waited online for a Covid-19 test.
"Based on previous response made by my community, if there's any emergency, I think supply can be guaranteed. Plus, there were lessons we learned from other cities. I think we can make good preparations."
The central city of Anyang, along with Dandong on the border with North Korea, also announced lockdowns as the omicron variant spreads across the vast country.
China's borders remain largely closed as its hardline response, and the pandemic's economic impact continues to grow.