(Yicai Global) April 20 -- Shanghai reported three more imported novel coronavirus cases yesterday, taking the eastern metropolis' total confirmed Covid-19 cases to 638, the city's health commission said this morning.

All the new additions were Chinese citizens. Two of them arrived in Shanghai from Russia and the third travelled from Japan, according to the commission. Authorities have traced 123 people who had been in contact with the patients during their journeys and placed them under quarantine, it added.

The commission confirmed no new domestically transmitted cases yesterday. It also reported no asymptomatic cases under observation in the city the same day.

Shanghai has confirmed 638 Covid-19 cases so far. Among the confirmed 299 imported Covid-19 cases so far, 109 patients are being treated, with one in serious condition, and 190 have been discharged upon recovery, the commission said.

It added 19 suspected cases, also involving people who have recently been overseas, who are undergoing further tests.

Of the 339 local cases, seven have died, one is in critical condition, and 331 patients have fully recovered and been discharged from hospital, the commission said.