GUANGZHOU, April 10 (Xinhua) -- Since April 5, the southern Chinese city of Guangzhou has started conducting nucleic acid detection on all persons who entered the city from high-risk countries, local authorities said Friday.

As of Thursday, Guangzhou had performed nucleic acid tests on about 4,355 personnel from high-risk countries and put them under health management, the Guangdong provincial health commission told a press briefing.

The health management refers to isolation for medical observation.

The move has detected a number of confirmed cases of COVID-19, said Tang Xiaoping, director of the provincial health commission.

Earlier, Guangzhou had carried out a comprehensive screening on people who entered the city from overseas since March 8 but have not been included in the home or centralized isolation medical observation. As a result, 21,742 inbound personnel have been put under health management and undergone nucleic acid tests.

Since March 15, Guangzhou had reported a total of 114 imported cases as of Thursday.