After the central Chinese city where the coronavirus first emerged announced its first local infections in more than a year, authorities in Wuhan stated on Tuesday that they would test the entire population for COVID-19.

At a press conference on Tuesday, senior Wuhan official Li Tao said the city of 11 million people is “swiftly launching comprehensive nucleic acid testing of all residents.”

The city had not recorded any locally transmitted infections in almost a year before Monday.

In the wake of the country’s worst coronavirus epidemic in months, China has restored severe restrictions, forcing citizens in some places to stay at home and strengthening testing.

In eastern China, the city of Yangzhou, near Nanjing, was the latest to issue a stay-at-home order after large-scale testing revealed 40 new infections over the past day, France 24 reported.

The city government announced Tuesday, Aug. 3, that the more than 1.3 million residents of Yangzhou’s urban centre are now confined to their homes, with each household authorized to send only one person outside every day to shop for necessities.

The announcement comes after the tourist destinations of Zhangjiajie and Zhuzhou in central China’s Hunan province issued similar orders to more than two million visitors in recent days.

People affected at the Nanjing airport cluster attended theater performances in Zhangjiajie, and the outbreak also expanded to Hunan last month.

After the coronavirus initially appeared in Wuhan, China boasted of its success in reducing domestic cases to almost zero, allowing the economy to recover.

With almost 400 domestic cases identified since mid-July, the new outbreak is threatening that success.