"If you need to go out, wear a mask, avoid large gatherings and maintain a distance of one meter from others," Hanoi Chairman Chu Ngoc Anh said in a new directive issued after the capital city recorded 21 local transmissions in the latest outbreak.

City authorities have already suspended festivals, religious rituals, sports tournaments and crowded events in public places and stadiums.

Traditionally, Tet or Lunar New Year is Vietnam's biggest and most important holiday, an occasion for spring festivals, large gatherings and parties.

Food and beverage shops that can pose infection risks should ensure social distancing of two meters between two persons and provide takeaway services, authorities have said.

In the transportation sector, all drivers and passengers must wear face masks and make medical declarations. Social distancing between passengers on vehicles is encouraged; and inter-provincial buses have to notifying the names and personal addresses of passengers to enable easier contact tracing in the event of any infection being detected.

Hanoi, less than two hours to the east of Hai Duong, the country's biggest Covid-19 hotspot at present, has locked down 10 areas where infections have been confirmed. The city has shut down all bars, karaoke parlors, and discotheques, as well as video game and internet parlors until further notice.

The city will only allow one firework show on Lunar New Year's Eve, instead of the originally planned 30; and no large gatherings to watch fireworks will be allowed.

Residents of Ho Chi Minh City, which has reported one community transmission in the new outbreak, have also been encouraged to wear face masks while visiting the famous Nguyen Hue flower street, a traditional event in the southern metropolis during the Tet holiday. The flower street will open on February 9, three days before Tet peaks.

Vietnam has reported 366 cases of community transmission within a week since the latest outbreak began on January 28 and spread to 10 localities. Many localities have suspended Tet festivities, scaled down fireworks shows and banned large gatherings.