The 11 cases comprise 10 members of the Revival Ekklesia Mission, a Christian congregation, and one person who had come into contact with the members.

The southern metropolis's latest coronavirus cluster was detected after three members of the mission with respiratory problems went to the Gia Dinh Hospital in Binh Thanh District on Wednesday. Tests showed they were positive for the novel coronavirus.

Contact tracing then unearthed several new coronavirus cases related to the three patients, amounting to at least 36 people as of Thursday evening. Of them, 29 are members of the mission and seven have had contact with them.

The infectees have lived, worked or had contact with people in 16 districts across HCMC. Nineteen people, or 53 percent of those related to the cluster, have shown symptoms.

These cases have yet to be confirmed by the Ministry of Health as Covid-19 patients.

The municipal CDC said the novel coronavirus might have been festering in the community, so citizens need to be on high alert, submit medical declarations and comply strictly with existing coronavirus prevention measures.

Authorities will carry out mass Covid-19 screening in the community, focusing on eight districts where members of the Revival Ekklesia Mission reside, said city chairman Nguyen Thanh Phong. Members of the parliamentary election committees in these districts would also be prioritized for testing, he added.

HCMC had confirmed just eight Covid-19 cases in Vietnam's latest wave before the new cluster was detected.