Wuhan, the central Chinese city where the novel coronavirus was first detected, is planning to conduct full-scale nucleic acid testing of its 11 million residents over the next 10 days, Sixth Tone’s sister publication The Paper reported Tuesday.

The city’s health authority issued an “emergency announcement” Monday after six new COVID-19 cases were reported over the weekend, all in the same residential community. The housing complex previously had a total of 20 confirmed COVID-19 cases, and authorities said the new cluster could be linked to “past community infection.”

Before the six cases, there had not been a single COVID-19 infection reported in all of Hubei province, where Wuhan is located, for 35 consecutive days.

The government official in charge of the area in Dongxihu District where the six cases were detected was removed from his post Monday for “ineffective lockdown and control management.”

On Apr. 14, Wuhan health authorities initiated a serological survey of some 11,000 residents. By looking for specific antibodies in their blood — evidence of a past or present infection — researchers would be able to estimate the true scale of the local outbreak, including asymptomatic carriers. According to the state-run online news outlet Xinhua Net, the survey result was expected on Apr. 22, though no data has been released as of Tuesday. (Image: People Visual)