Officials in Shanghai have ordered the city's 26 million people to take PCR tests amid a record coronavirus surge, but anger continues to grow over the way authorities are tackling a surge of cases.

The Chinese government sent its military and thousands of healthcare workers to the city to conduct mass testing. It's China's largest public health response since the initial outbreak in Wuhan in early 2020.

Officials in Shanghai reported a record high of more than 9,000 new cases on Sunday. The situation is seen as a test of China's hardline "zero-COVID" approach.

Residents have complained about a lack of access to medical care and food during the city's sweeping lockdown which began last week. It was supposed to end for people in half of the city on Friday, but officials decided to extend the measures in most areas.