Staff members check the information of passengers entering China at the Pudong International Airport in Shanghai, east China, March 18.Photo:Xinhua

Shanghai reported eight imported COVID-19 cases in the past 24 hours. The eight patients, all Chinese nationals, took the same flight to the Chinese city from Russia, Shanghai authority announced Monday.

The patients have been transferred to designated medical institutions for treatment. 188 close contacts on the same flight have been tracked and will undergo isolation for medical observation.

They departed from Russia on December 17 and arrived at Shanghai Pudong International Airport on December 18. Upon their arrival, they began their quarantine period at a designated place, during which they developed symptoms, the authority said.

Shanghai has recently seen more COVID-19 cases imported from Russia. The Civil Aviation Administration of China, the country's civil aviation regulator, issued an eight-week "circuit breaker" on Friday for flight SU208 operated by Russia's Aeroflot, after 14 passengers on the flight from Moscow to Shanghai returned positive nucleic acid test results for COVID-19 on Dec 11.

As of 11:10 on December 20 (local time), Russia recorded over 2.8 million cases, with a total of 50,858 deaths.