Most of the new cases were detected in Hanoi, at 2,505. It was followed by Tay Ninh with 862 cases and Hai Phong, 792 cases.
In the past 24 hours, 230 Covid-19 patients have died, including 25 in Ho Chi Minh City.
Since the pandemic started last year, the death toll in Vietnam has climbed to 33,475, or 1.8 percent of all infections.
In the latest wave that hit the country in late April, more than 1.81 million cases have been confirmed and 1.44 million of them have recovered.
So far, 69.8 million people, or over 72 percent of the population, have been fully vaccinated.