Seven cases were recorded in Bac Giang, four in Hung Yen, four in Thai Binh, three in Hanoi and one each in Thua Thien-Hue, Ha Nam and Hoa Binh.

The seven cases in Bac Giang are associated with an outbreak at electrical appliance manufacturer SJ Tech company. They are being treated at a local field hospital

The four cases in Hung Yen are close contacts of previously confirmed Covid cases at already detected hotspots. They are being treated at the National Hospital for Tropical Diseases.

The four cases in Thai Binh are also close contacts with a previously confirmed Covid case. They are now treated at the Thai Binh General Hospital.

The three cases in Hanoi are all men aged 40, 42 and 44. One of them, an Austrian, flew from Da Nang, now a coronavirus hotspot, to Hanoi's Noi Bai Airport on Vietnam Airlines flight VN160 on April 29. He medically declared himself to authorities and is currently in centralized quarantine at the capital.

The other two cases, residing in Ha Dong District, are both close contacts with confirmed coronavirus cases.

The case in Thua Thien-Hue is a 58-year-old woman who has made contact with previously confirmed coronavirus cases. She has been quarantined already and is being treated at the Hue Central Hospital.

The case in Ha Nam is a 36-year-old man who flew from Da Nang to Hanoi on the same VN160 flight on April 29. He medically declared himself and was put into centralized quarantine. He's being treated at the National Hospital for Tropical Diseases.

The case in Hoa Binh is a 62-year-old woman who has made contact with a confirmed coronavirus cases. She's also been quarantined and is being treated at the Hoa Binh General Hospital.

Vietnam's new Covid-19 wave has seen 665 community cases recorded in 26 cities and provinces since late last month.

Over 942,000, or 1 percent of the country's population, have been vaccinated against Covid-19.