In the Chinese metropolis of Guanghzou, mass tests were ordered for millions of residents on Wednesday after a sharp increase in the number of corona infections.
Five of the eleven districts are affected, including Haizhu, which alone has more than 1.8 million people and the majority of cases have occurred.
County-wide lockdown
A district-wide lockdown from Saturday to Monday was extended to Friday in light of the rising number of cases.
More than 2,000 new cases have been reported for two days in a row in the worst outbreak to date in the major trading hub dubbed the 'factory of the world'.
Across China, the number of new local cases hit the highest level since April 30.
Metropolises such as Beijing, Zhengzhou and Chongqing are also struggling with increasing numbers of infections, which dampens hopes that China could soon relax its strict zero-Covid policy.
The country's economy is severely affected: In October, Chinese producer prices fell for the first time in almost two years.
Conversely, consumer price inflation moderated, partly as a result of the tightened coronavirus lockdown.
The growth of the world's second-largest economy has slowed significantly in recent months amid the strict zero-Covid policy to contain the virus.
Almost three years after the outbreak of the pandemic, it continues to affect supply chains and also impacts production and consumption.
Although the number of cases in China is low in global comparison, the government is strictly on course.
Mass testing for large populations has been the norm since 2020.