However, local health authorities have confirmed there is no likelihood of community transmission from the latest patients as they were all quarantined after the flight landed at Van Don International Airport in the northern province of Quang Ninh.
There have been no community transmissions of the virus for 29 days and no deaths.
The new cases, aged between 24 and 47, include one woman and 23 men. One is being treated at the Field Hospital No. 2 of Quang Ninh and the rest are at Thai Binh Provincial General Hospital.
The flight from Moscow landed on May 13 and was carrying mostly children under the age of 18, students, the elderly, sick people, tourists and people whose visas had expired but could not leave the country.
The 345 repatriated citizens as well as the crew from the Vietnam Airline flight were all immediately quarantined.
The country’s total recovered cases now stand at 260 after eight patients with COVID-19 were declared to have recovered on May 14 afternoon.
Of the 52 active cases including 24 new cases, five patients have tested negative for SARS-CoV-2 once and other nine have tested negative for the virus more than twice.
As many as 12,236 people are under quarantine, including 353 at hospitals, 8,492 at concentrated quarantine areas and 3,391 at home. They either returned from abroad or came into close contact with confirmed cases.