"People should stay at home as much as possible. If one needs to go out, wear a mask and maintain distance from other people," Nguyen Duc Chung, Chairman of the Hanoi People's Committee, said Monday.

Vietnamese and foreigners entering Vietnam are some of the most likely sources of infection, Chung said. Hanoi has recorded 39 Covid-19 cases so far, 30 of them coming in from other countries and territories, he said.

He said authorities must continue the process of identifying everyone who has entered Vietnam from March 7 onwards and are residing in Hanoi but are yet to be quarantined, so that they can be monitored and quarantined if necessary.

Hanoi confirmed its first infection late on March 6, which is also Vietnam's first case after 22 clean days. Since then, the country has recorded 107 cases, with one discharged from hospital after recovery last week.

Chung said that people who have a fever, cough or shortness of breath will need to be transferred to a hospital promptly.

Family members of people quarantined are also requested not to supply more items as the quarantine zones have provided enough already, Chung said.

As of Monday, all Covid-19 patients in Hanoi were being treated at the National Hospital for Tropical Diseases in Dong Anh District. Less severe cases were transfered to other hospitals in the city on Tuesday morning to ease the load.

Vietnam has recorded 123 Covid-19 cases so far, 17 of whom have recovered and been discharged. Many of the remaining people in hospitals, are Vietnamese and foreigners arriving from Europe and the U.S.

The pandemic has thus far spread to 195 countries and territories, killing more than 16,500 people.