China is once again mass testing an entire city for the coronavirus amid a regional outbreak in Xinjiang province.
Around 4.7m people in Kashgar are being tested and 138 asymptomatic cases have been found so far.
China has been largely successful in bringing infection rates down but there continue to be small outbreaks.
Xinjiang is home to China’s mostly-Muslim Uighur minority which rights groups say is being persecuted by the government in Beijing, reports the BBC.
Schools in Kashgar have been closed and residents are not allowed to leave the city unless they have a negative test report.
The first case in the Kashgar outbreak was an asymptomatic woman working in a garment factory in Shufu county on the outskirts of the city.
Testing positive on the weekend, she was the first local case detected in mainland China for 10 days.
Since the widespread testing got under way on Saturday, another 137 asymptomatic cases have been reported.
More than 2.8 million tests had been conducted and the rest will be completed within two days, according to city officials.
Kashgar is in China’s western Xinjiang province, which is home to ethnic Uighurs and other Turkic Muslims.
The province has a network of detention camps which China says are needed to tackle extremism while rights groups see them as part of a campaign to suppress the culture, language and identity of the Muslim minority.
The US recently blocked some exports from Xinjiang over alleged human rights abuses and forced labour.
While normal life has resumed in much of China, there continue to be small outbreaks that authorities have chosen to tackle with immediate mass testing.
Earlier in October, the city of Qingdao tested its entire population of nine million people .
In May, China tested the entire city of Wuhan – home to 11 million people and where the novel coronavirus was first identified.