Medical workers prepare to take swab samples from residents for coronavirus tests in Dalian's Jinpu New Area in Liaoning province on Monday. (Photo by Wang Feng/For chinadaily.com.cn)

The port city Dalian, Liaoning province, reported one confirmed COVID-19 case and eight asymptomatic ones on Tuesday, officials said in a news release on Wednesday.

From Dec 15 through Tuesday, the city reported six confirmed, domestically transmitted COVID-19 cases and 20 asymptomatic, domestically transmitted cases.

The new confirmed patient, surnamed Liu, 58, is the mother of a previous asymptomatic case. She lived in a residential compound of Youyi street community in Dalian Jinpu New Area.

As a close contact of her son, surnamed Su, Liu was tested on Tuesday and the result came back positive. She was transferred to the designated hospital in Dalian and was diagnosed as a confirmed case.

The eight new asymptomatic cases were discovered at medical institutions and in screening tests conducted in medium-risk zones.

Patients have been transferred to the designated hospital for quarantine and treatment.

People who had close contact with the new cases, and in turn their own close contacts, are being investigated and quarantined for medical observation.