China has seen a decline in new locally transmitted COVID-19 cases in recent days, with the outbreak being contained in Dalian, Liaoning province, and a slowing of the spread of the disease in Urumqi, capital of the Xinjiang Uygur autonomous region.

The recent outbreak in Dalian has been contained in a timely manner with effective measures, and it may have been triggered by imported sources, a health official said at a news conference on Aug 3.

"It has not yet spread to a wider region, but uncertainties and risks remain high," said Zhao Zuowei, director of the Dalian Health Commission.

Zhao said that the possibility of domestic transmission can be preliminarily ruled out, but the possibility of infection triggered by imported sources from abroad cannot be dismissed.

Efforts to trace the source of the recent outbreak are in progress under the guidance of national and provincial experts, he said.

The northeastern port city identified eight new confirmed cases on Aug 2. The total number of confirmed cases with symptoms climbed to 87, while the number of asymptomatic carriers dropped to 27, said the local health authority.

Investigations found no clues that the outbreak in Dalian was related to the recent cases in Beijing and Xinjiang, he said.

The first case in the city was an employee of a seafood processing workshop, where a total of 60 people were infected, accounting for 61.9 percent of all people working there, Zhao said.

In Urumqi, officials said the growth in confirmed COVID-19 cases has been flattening in recent days as the number of new daily infections dropped for four consecutive days.

The northwestern city reported 28 new confirmed locally transmitted infections and eight new asymptomatic cases on Aug 2, bringing the total number of confirmed cases to 586 and asymptomatic carriers to 114 as of Aug 2.

Shang Yulan, deputy secretary-general of the city government, said a total of 30 patients had recovered and discharged from hospitals in Urumqi since the outbreak started on July 15.

"Though the situation in Urumqi has shown positive change with strict prevention and control measures taken by the city, Urumqi will continue to ensure and implement the effective measures to achieve an early victory against the epidemic," Shang said during a conference on Aug 3.

Meanwhile, the city has taken measures to protect workers, especially migrant workers at key engineering projects, to prevent the spread of the disease and ensure supplies of daily necessities.