The southern metropolis recorded 51 patients and they are all related to Revival Ekklesia Mission, a Christian congregation based in the city's Go Vap District that is the biggest Covid-19 cluster ever in HCMC.

Since its emergence last Wednesday, the cluster has been responsible for 202 cases that are registered in HCMC and five other localities - Bac Lieu, Binh Duong, Long An, Tra Vinh in the south and the Central Highlands province of Dak Lak.

The remaining cases reported Tuesday morning are in Bac Giang Province and its neighbor Bac Ninh in the north, both home to industrial parks housing major foreign manufacturing plants.

In Bac Giang, 45 patients are related to clusters at its industrial parks and have all been isolated before testing positive.

In Bac Ninh, 15 cases are those who had contact with Covid-19 patients and have already been isolated following contact tracing.

Over a month into its fourth wave, which is by far the most challenging that Vietnam has encountered, the country has recorded 4,357 cases in 36 of its 63 cities and provinces.

Bac Giang is leading the case count with 2,297 infections, followed by Bac Ninh with 857, Hanoi with 412 (including 93 in a locked down hospital) and HCMC with 208.

More than 1.1 million of the nation's 96 million have been vaccinated against the new coronavirus.