A health worker disinfects the house of patient 418 in Hai Chau district, July 26, 2020.

The municipal People's Committee said the order is effective until further notice.

It bans any gathering of over 30 people and urge locals to keep a minimum distance of one meter in work places, schools and hospitals.

Festive activities, religious ceremonies, sports tournaments and crowded events in public places, stadiums, and big venues are prohibited.

The central city also suspends operations of "non-essential" services like amusement parks, beauty facilities, karaoke and massage parlors, and bars.

It also stops receiving tourists for the next 14 days. 

Other protective measures include reducing the numbers of students in classrooms and encouraging people to wear face masks.

The move comes after Da Nang recorded two domestic transmission cases in the past few days, ending Vietnam's 99-day streak of no community transmission.

"Patient 416", a 57-year-old man in Lien Chieu district, had tested positive for the novel coronavirus five times as of Saturday morning. He remains in critical condition.

"Patient 418", 61, also a Da Nang resident, is in severe condition and needs ventilation support, doctors said.

Authorities have yet to confirm the source of transmission for the two cases.

The National Steering Committee for COVID-19 Prevention and Control on Sunday proposed the Prime Minister to deploy 15-day social distancing in the city, starting from midnight the same day.

It said means of public transport to and from Da Nang must be restricted, with only one or two domestic flights allowed.

The Health Ministry has established 3 anti-COVID-19 special task forces to aid Da Nang.

Vietnam had recorded 418 novel coronavirus cases as of Sunday morning, of these 365 have recovered.

On Saturday, Prime Minister Nguyen Xuan Phuc ordered tightened management of border gates from the north to the south to prevent illegal entry.