The four imported patients included three who entered Vietnam through Moc Bai International Border Gate in Tay Ninh Province and one through Thuong Phuoc International Border Gate in Dong Thap Province.
The patients are now being treated at local hospitals.
With these new infection cases, the number of Covid-19 patients in Vietnam has increased to 2,448, including 849 locally-transmitted cases reported since the new outbreak started in Hai Duong on January 28. Hai Duong Province alone has recorded 665 cases.
As of 6 pm on February 28, a total of 1,876 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, as many as 63,054 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.