On Wednesday, people in neighbourhoods and workplaces in the northern city of Xi'an were ordered to stay at home unless they had a pressing reason, state media reported.
All transport to and from the city has been suspended, except in special cases and the lockdown saw people panic buying.
Social media posts reportedly suggested groceries and household products were being snapped up by panic buyers, with the government saying new supplies would be brought in.
Residents posting on Thursday, however, said the situation remained relatively calm, with people allowed to travel in and out of the compounds in which they live.
Every two days, one person from each household will be allowed to leave the home to buy necessities and there has been no word of when the restrictions will be lifted.
On Thursday, Xi'an reported 63 new locally acquired cases in the past 24 hours, pushing the city's total to 211 over the past week.
The restrictions in the northern city are some of the strictest China has imposed since the start of the pandemic, when Wuhan's 11 million people were plunged into lockdown after the coronavirus was first detected.
In China, there have been seven confirmed cases of the Omicron variant, four in manufacturing centre of Guangzhou, two in the southern city of Changsha and one in the northern port of Tianjin.
There has been no confirmation the cases in Xi'an are the Omicron variant, or Delta.
In the eastern province of Zhejiang near Shanghai, there has been a substantial outbreak and isolation measures have been narrowly targeted.
Strict pandemic control measures have been adopted in China, seeking to get new transmissions down to zero, meaning there has been frequent lockdowns, masks and mass testing.
The policy has not been entirely successful, leading to massive disruptions in travel and trade but Beijing credits it with largely containing the spread of the virus.
The measures have been ramped up in recent days as China prepares for the Beijing Winter Olympic Games on February 4.
China has reported 4636 deaths among a total of 100,644 cases of Covid-19.
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