The cases, who are from Dong Trieu Town in the northern province of Quang Ninh, are being treated at Vietnam-Sweden Hospital in Uong Bi District. Two of them are a couple.
By 6 am on Tuesday, Vietnam had a total number of 1,163 Covid-19 community transmission cases, including 470 since January 27.
The country has witnessed 35 deaths related to Covid-19.
At present, 89,782 are being quarantined, including 529 at hospitals and the remainder from quarantine sites and houses.
