Photo: Xinhua

HARBIN, Dec. 11 (Xinhua) -- Dongning and Suifenhe, two cities in northeast China's Heilongjiang Province, have launched citywide nucleic acid testing, local authorities said on Friday.

It is expected that tests will be completed in three days. The campaign was initiated after each city reported a domestically transmitted COVID-19 case on Thursday.

Dongning has set up eight sample collection points and dispatched more than 320 personnel to carry out nucleic acid tests, said city mayor Zhou Zhenhai, adding that Dongning has sampled 10,430 people as of 9 p.m. on Thursday.

One residential compound in Suifenhe was classified as a medium-risk area for COVID-19 on Friday, according to the city's COVID-19 epidemic prevention and control headquarters.

Four hotels in Suifenhe have been designated as centralized quarantine sites and placed under closed management.

The city has also tightened the control of personnel flows. A negative nucleic acid test certificate issued within one day of travel is necessary for those who are required to leave Suifenhe.

Epidemiological surveys and source tracing work concerning the COVID-19 patients are underway in the two cities.