The two imported cases were found in Long Binh border gate and were quarantined immediately after entry in An Giang province.
Among the two locally-infected cases, the case found in Da Nang city began to display Covid-19 symptoms of fever and fatigue on April May 1 and tested positive for the coronavirus the next day.
The case found in Hanoi is a passenger who sat near two Chinese experts, had once worked in Vietnam and had later been confirmed positive for the virus after returning back to their country from Vietnam, on Vietnam Airlines flight VN160 from Da Nang to Hanoi on April 29.
The new cases raised the national infection tally to 2,985, including 1,607 locally-infected cases and 1,378 imported ones.
Among the overall figure, a total of 2,560 coronavirus patients have been declared free from the virus, while fatality count related to COVID-10 remains unchanged at 35.
Furthermore, 74 of those still receiving treatment have tested negative for the virus at least once, with most of them reporting negative results.
In addition, more than 40,500 people who are currently in quarantine nationwide after having close contact with COVID-19 patients or entering Vietnam from pandemic-hit regions.
Vietnam has so far recorded a total of 36 community transmission cases since April 29 in Ha Nam, Hanoi, Hung Yen, HCM City and Vinh Phuc.
The country has vaccinated over 539,000 people against Covid-19, mainly frontline workers of the Covid-19 fight along with members of community-based anti-COVID-19 groups from March 8 to May 3.
In an effort to slow the coronavirus spread, the nation has put a score of COVID-19 response measures in place across many pandemic-hit localities, including Hanoi and Ho Chi Minh City.
Hanoi is among five other pandemic-hit localities that has decided to allow students stay indoors amid new coronavirus outbreaks.
The decision came after the capital detected three community locations from a coronavirus outbreak in northern Ha Nam province, a large number of returnees to the city after a four-day Reunification Day and May Day holiday since April 30.