All of them are local residents in Hai Duong and link to people that have already been infected with the new coronavirus ever since the province became the Covid-19 hotspot on January 28.
With them added to the list, Vietnam has recorded 418 domestic cases in the past 10 days.
Infections have so far spread to 12 cities and provinces, including 309 in Hai Duong alone and 47 in its neighbor Quang Ninh.
Hanoi is still the third most affected in this new wave of community transmissions, recording 23 cases while HCMC gets two.
By far, Vietnam has got 2,001 cases and 1,472 of them have recovered, including four on Sunday.
Worldwide, Covid-19 has killed more than 2.32 million after over 106.42 million were infected.