The city's lockdown follows the closure of Xi'an, a city of 13 million people in neighboring Shaanxi Province of Northwest China.
Located 500 km from Yuzhou, Xi'an did not announce a lockdown until more than 100 people contracted the virus and might have led to a much worse situation.
As of Monday, Xi'an has reported more than 1,600 cases in the latest flareup of COVID-19.
On Sunday night, the city issued a notice on epidemic prevention suspending all kinds of public transportation and public gathering activities after two asymptomatic infections were detected and transferred to the designated hospital for treatment.
Epidemiological checks of the two silent cases showed that they had never traveled to other places in the past 14 days.
According to the notice, all the buses, taxi cabs, car-hailing services and public transit in the city were suspended. Shopping malls and supermarkets around the city also suspended all their operations except keeping supplies for daily necessities. Onsite teaching activities at schools were suspended.
Museums, stadiums, tourist attractions, chess and card rooms, internet cafes and other enclosed entertainment and leisure places were ordered to halt operation.
Downtown area in the city was locked down with all personnel not allowed to enter or exit the area. People returning to the city have to report proactively to their communities or companies.
Workers from industries that are essential to epidemic prevention, such as production, transportation and sales of medicines and prevention equipment have to register and go to work with certificates issued by their companies.