Most of the new cases were detected in Hanoi, at 1,646. This was the third day in a row that the capital led in the number of new cases.
It was followed by Ca Mau with 1,193 new cases and HCMC with 979 cases.
In the past 24 hours, 210 Covid-19 patients have died, including 46 in HCMC. Hanoi recorded five deaths.
Since the pandemic started last year, the death toll in Vietnam has climbed to 30,251, or 1.9 percent of all infections.
In the latest wave that hit the country in late April, more than 1.58 million cases have been confirmed and 1.17 million them have recovered.
So far, 65.6 percent of the population have received two doses of vaccine.