They include a 34-year-old woman working at Poyun Vietnam Electronics Co. Ltd in Hai Duong Province that neighbors Quang Ninh.

The other two patients are a married couple, aged 61 and 60.

All three are residents in Quang Ninh's Dong Trieu Town.

Poyun Vietnam is where one of the first two cases of the nation's new community transmissions wave was detected on January 28. The other case was a man working at Van Don International Airport in Quang Ninh.

With three more patients added, Vietnam has registered 470 domestic infections since January 28 and cases have spread to 12 cities and provinces.

Hai Duong and Quang Ninh stand at the top as the most infected, with 321 and 53 cases each.

HCMC comes third with 31, including 29 recorded on Monday. Of the HCMC cases, just one has been confirmed to link to the hotspot in Hai Duong while the source of transmissions for the remaining cases, linked to Tan Son Nhat International Airport, has remained unclear.

The southern metropolis is followed by Hanoi with 26 cases, Gia Lai Province with 21 cases, Binh Duong Province with six, Bac Ninh Province with four, Dien Bien Province with three, Hoa Binh Province with two, and Hai Phong, Bac Giang and Ha Giang Provinces with one each.

Vietnam has recorded 2,053 Covid-19 patients, including 543 active cases.

Globally, the pandemic has killed more than 2.3 million people among nearly 107 million infections.