China’s government says all 9 million people in the eastern city of Qingdao will be tested for the coronavirus this week after nine cases linked to a hospital were found.

The announcement broke a string of weeks without any locally transmitted infections reported in China, though the country has a practice of not reporting asymptomatic cases. The National Health Commission said authorities were investigating the source of the infections found in eight patients at Qingdao’s Municipal Chest Hospital and one family member.

The commission said the whole city will be tested within five days.

China only has reported a handful of cases since the spring.