Illustrative photo.
According to the ministry's report, two of the newly-reported patients are male crewmembers aged 44 and 26 of the Navios Marco Polo ship which arrived at the Nha Trang Port from Ukraine on December 9.
They were sent to a quarantine area in Khanh Hoa Province upon arrival and tested positive for SARS-CoV-2 on December 11.
The two patients are now being treated at the Khanh Hoa Provincial Hospital for Tropical Diseases.
The other two patients are two men aged 26 and 46 who recently returned from Russia and the UAE.
They were sent to quarantine areas in Danang City and Phu Yen Province upon arrival and are now being treated at local hospitals.
Earlier, several people who boarded the same flights with these two patients were also reported to have coronavirus.
With these new infection cases, the number of imported Covid-19 patients in Vietnam has increased to 701.
As of 6 pm on December 12, a total of 1,238 Covid-19 patients had recovered and been discharged from hospital. There have been 35 deaths, most of them being the elderly with serious underlying diseases.
At present, over 21,000 people who had close contact with Covid-19 patients or returned from virus-hit areas are being monitored at hospitals, quarantine facilities, and at home.