Of the new patients, 138 were recorded in the northern Bac Giang Province and they are all linked to clusters at its industrial parks.
HCMC got 38 cases, including 31 that have had direct contact with previously confirmed patients and two linked to the Christian congregation cluster emerging on May 26 in Go Vap District. For the remaining five cases, the health authorities are still investigating their source of infection.
Bac Ninh Province that borders Bac Giang reported 21, including 16 related to clusters at its industrial parks, two linked to a hotspot in Thuan Thanh District, and two having had contact with Covid-19 patient. The source of transmission of the remaining case is still unclear.
Binh Duong Province, a HCMC's neighbor, recorded 12 cases that are all linked to two previously confirmed patients.
The case in northern Lang Son Province is a 26-year-old woman linked to the cluster at the Quang Chau industrial park in Bac Giang.
Tuesday's infection tally is the second highest daily number since the fourth wave broke out in Vietnam, only after 444 recorded on May 25.
With the new patients added, Vietnam has recorded 7,997 local Covid-19 cases in 40 cities and provinces since the new wave started on April 27.
Bac Giang has continued to have the highest infections so far, with 4,401 cases, followed by Bac Ninh with 1,415 and HCMC with 961.
Since April 29, Vietnam has tested almost 4.82 million people.