The northern province, the biggest Covid-19 hotspot, hosted 38 of the 40 new cases. Its neighbors Quang Ninh and Hanoi had one each.

"Patient 2272" in Quang Ninh Province had close contact with a previously confirmed Covid-19 patient and had already been quarantined since earlier this month in line with the contact tracing protocol. The patient's third testing result on Tuesday came back positive. The patient is being treated at a hospital in Quang Ninh.

"Patient 2273" in Hanoi also had close contact with a previously confirmed Covid-19 patient and is receiving treatment at the National Hospital for Tropical Diseases in Hanoi.

Among 38 cases in Hai Duong, tagged from 2274 to 2311, 34 had close contact with previously confirmed coronavirus cases and had already been quarantined since last month while four other cases were detected after they came to local drug stores to buy medicine for fever and cough.

They are being treated at a local field hospital.

Hai Duong, the epicenter of a new coronavirus outbreak that has swept through 13 cities and provinces since late last month, entered a 15-day social distancing starting Tuesday to stem the spread of the virus.

For fears of cross-infections inside quarantine zones, authorities in Hai Duong Tuesday said surveillance camera will be installed at 103 centralized isolation facilities.

At least 28 localities in Vietnam have allowed students to stay home after the Tet break, which wraps up on Tuesday, amid the complicated development of the pandemic. Schools had been scheduled to resume on Wednesday.