The Chinese mainland reported 19 newly confirmed COVID-19 cases on Thursday－nine of them locally transmitted and 10 imported－the National Health Commission said in a daily report published on its website on Friday.

Five of the locally transmitted cases were reported in Beijing and four in Liaoning province, it said.

Two of the cases in Liaoning were in Shenyang, the provincial capital, and two in the port city of Dalian, the Liaoning Provincial Health Commission said on Friday. Dalian also reported three asymptomatic cases, all locally transmitted.

Shenyang classified another five areas in the city as medium-risk COVID-19 zones on Friday, the provincial health commission said. The mainland now has 33 medium-risk COVID-19 areas, with five in Beijing, 10 in Shenyang, 16 in Dalian and two in Heihe, Heilongjiang province. There are no places classified as high-risk.

Shenyang has imposed lockdown measures on its medium-risk areas, banning all their residents from leaving the city. People living in other parts of the city have been urged to avoid traveling elsewhere unless absolutely necessary.

Those who do need to leave the city must have a negative result from a nucleic acid test conducted within the past 72 hours, according to a regulation released by Shenyang's COVID-19 epidemic prevention and control headquarters that came into force on Friday.

Chengdu, Sichuan province, which reported 14 cases in an outbreak from Dec 7 to 17, has lowered the risk level in all its formerly medium-risk areas to low because no additional positive results were reported for 14 days, the city's health commission said in a notice published on its WeChat account on Thursday.

The outbreak in Chengdu was traced to imported cases from Nepal, the notice said.

Some people from Nepal who arrived in Chengdu were put under quarantine for medical observation in a village in Chengdu's Pidu district on Nov 9. Five of them tested positive for coronavirus infection in nucleic acid tests on Nov 16 and Nov 28.

Staff members working at the quarantine place failed to put trash in designated places, the notice said. The first patient was probably infected by touching the trash and spread the coronavirus to the other patients.