The latest round of COVID-19 cases in Shenyang, Northeast China's Liaoning province, was ignited by a person who returned from overseas after being released from quarantine, local authorities revealed at a news conference on Monday.

This person's activities, including going to hospitals and contacting family members and residents in a local community, caused some infections and spread to relatives and in public areas, according to Sun Baijun, director of Shenyang's Disease Prevention and Control Center.

As of Sunday, the city has reported 37 confirmed cases and one asymptomatic carrier. One department store, one bus, one clinic, two pharmacies, and four hospitals were involved.

The field epidemiological investigation and laboratory analysis are still ongoing, Sun said.

Health officials from Dalian, another city in Liaoning, said on Monday the people and goods involved in the source of the city's latest outbreak have been effectively controlled and the source of the outbreak has been eliminated.

All sources of the city's 51 confirmed cases and 32 asymptomatic infections in the latest round have been identified, said Zhao Lian, deputy director of the city's Health Commission, at a news conference on Monday.

As revealed previously, the latest round of COVID-19 cases in Dalian was ignited by five dockworkers unloading imported contaminated cold-chain cargo from a Russia-owned ship, Zhao said.

By Monday, 29 confirmed cases and 17 asymptomatic infections had been discharged from a hospital in Dalian.