A medical worker collects a sample from a resident at a nucleic acid testing site in Zhenhai district in Ningbo, Zhejiang province on Dec 6, 2021. [Photo provided to China Daily]

Ningbo in East China's Zhejiang province reported 11 new cases of COVID-19 between Dec 6 and Dec 7.

Eight cases were detected during mass testing which began on Dec 6 after three cases were reported in Zhenhai district that same day.

Ningbo upgraded its emergency response to the highest level starting at 2:00 am on Dec 7 and imposed closed management across the district.

Testing was also expanded from just the residents in Zhenhai's Jiaochuan sub-district, where the three infected patients live and work, to all residents of the district.

The first round of nucleic acid tests in Zhenhai district, excluding the Jiaochuan sub-district, was completed on Dec 7, with more than 410,000 samples taken. All tests returned negative.

To prevent the spread of the virus, the city will conduct another testing campaign in the Jiaochuan sub-district from 8:00 am to 2:00 pm on Dec 8.

Residents are required to bring their smart phones and identity cards to the designated places for nucleic acid testing.

While queuing for the test, people must wear surgical masks and maintain social distancing of at least a meter.

Those who fail to take the tests in time and cause the spread of the virus will have to bear the legal ramifications.