Authorities in Quang Ninh, which is nearly 150 km east of Hanoi, have closed all tourist attractions, relics and historical sites, including Ha Long Bay, a UNESCO heriage site, and its neighbor bay Bai Tu Long. Religious sites have also been suspended.

Hai Phong, around 120 km east of Hanoi and home to Do Son Beach and UNESCO heritage site Cat Ba National Park, similarly closed all tourist, historical and religious sites as well as amusement centers and street food stalls.

The National Hospital for Tropical Diseases in Hanoi's Dong Anh District, a frontline facility in the Covid-19 fight, has found 22 cases of infection, but the source of the transmission has not been identified. Hanoi has recorded 27 cases in total since the country's latest outbreak began on April 27.

Previously, Hanoi and the northern provinces of Thai Binh, Nam Dinh, Hung Yen, Ha Nam, and Vinh Phuc have closed all tourist sites and suspended non-essential services like bars and karaoke parlors.

Ha Nam and Vinh Phuc are now Covid-19 hotspots with 14 cases each. Other localities recording community transmissions are Hung Yen (two cases), Da Nang (2), Ho Chi Minh City (1), Yen Bai (1), Quang Nam (1), Dong Nai (1) and Hai Duong (1). In all, 64 people have been diagnosed with the disease since April 27.

Since Monday many pedestrians-only streets and night markets across the country have been closed amid a surge in infections.