The People’s Committee of Thanh Khe District in Da Nang imposed fines of VND5-10 million ($215.75-431.51) on the group for violating social distancing measures by gathering in public.
"We applied the maximum fine," said Ho Thuyen, chairman of the district committee.
The committee also fined the owner of the karaoke parlor VND40 million for not closing during this period and letting customers use banned substances on-site.
The group were caught using drugs at the parlor on August 9. Two of them, Pham Ba Hao, 32, and Tran Kim Trong Tin, 26, have been detained facing charges of organizing drug use, while others were fined VND500,000 to 1 million each for using drugs.
Da Nang, Vietnam's Covid-19 hotspot imposed social distancing measures on July 28 and they are still in effect.
Residents are required to stay home, only go out to buy food or medicine, work in factories or manufacturing facilities, or act as service providers or in case of emergency.
Public gatherings are limited to two people and a minimum distance of two meters between each other must be maintained.
Da Nang was the first locality in Vietnam to record a Covid-19 community transmission in 99 days on July 25.
Since then, the city has reported 389 Covid-19 cases. At present, 130 patients are receiving treated, 215 have recovered, and 30 have died.