Of these, 19 are members of the Revival Ekklesia Mission, which introduces itself as a Christian congregation, a non-denominational, evangelical, charismatic church planted in the 1990s.

Six others have had contact with the infected members.

The cluster was detected after three members sought health checks with respiratory conditions at Gia Dinh Hospital in Binh Thanh District on Wednesday and tested positive.

One of them is a 38-year-old woman living in Hoc Mon District and working in Phu Nhuan District.

The other two, who are husband and wife, live in District 12.

Following contact tracing, 22 more people have been found positive with the coronavirus, HCMC Center for Disease Control said Thursday morning. One of them works as a chef at Sheraton, the center said.

All 25 people have not been confirmed as Covid-19 patients by the Health Ministry, pending further test results.

Initial investigations found close contacts of the positive cases live across 16 of the city's 24 districts.

City authorities have locked down Alley 415 on Nguyen Van Cong Street, Go Vap District, where members of the mission gather.

More than 100 people living in the alley have had their samples taken for coronavirus tests.

Sheraton Hotel in District 1 has also been locked down.

The Sogetraco building on Dang Van Street in Phu Nhuan District, where the 38-year-old woman works, has also been isolated. A total of 72 people working at the building have been isolated and tested.

All shops and stores around the building have to shut until more test results are available.

Gia Dinh Hospital has conducted disinfection. The hospital does not have to shut down as the three people were isolated soon upon arrival.

HCMC has confirmed eight local patients in the new Covid-19 wave that started a month ago, including seven detected the past 10 days.