Of the 56 local infections, 16 cases were recorded at the National Hospital for Tropical Diseases in Hanoi, the country’s biggest coronavirus hotspot at the moment.
Bac Ninh, a gateway to Hanoi capital, reported 12 cases, emerging as a new coronavirus hotspot in Vietnam.
Vinh Phuc, which is a coronavirus hotspot linked to the Sunny bar outbreak, announced 11 cases. It was followed by Thai Binh 5, Hanoi 4, Da Nang 3, Hung Yen 2, and Hai Duong, Lang Son, and Quang Ngai one each.
Vietnam is seeking to contain the fourth wave of COVID-19 which has spread to 14 cities and provinces across the country with 120 cases detected over just eight days.
Epidemiologists have identified the sources of infection at Vinh Phuc and Ha Nam hotspots, but the sources remain unknown at the hotspots at the National Hospital for Tropical Diseases and in Da Nang.
Military forces were deployed on May 6 to disinfect the hospital which is being put under a lockdown order until May 19.
Despite its outbreak, the hospital which has received and treated more than 1,000 COVID-19 patients without a single death for more than a year continues to receive new patients for medical surveillance and treatment.
The same day, the Ministry of Health also announced four Vietnamese patients returning from overseas. Three of them tested positive during their stay in concentrated quarantine facilities, while the remaining case, a woman of Ha Tinh province, tested positive after completing her mandatory 14-day quarantine period.
Amid worries about the incubation period for COVID-19 lasting longer, the Ministry of Health recently decided to extend the mandatory quarantine time for people in close contact with COVID-19 patient or returning from overseas to 21 days.