The 28-year-old man, tagged as "patient 1342," has been suspended for his actions "that led to serious consequences," the carrier said in a statement.

Prime Minister Nguyen Xuan Phuc had sought an explanation from it after at least three locally transmitted cases were found in HCMC.

The flight attendant had returned to Vietnam from Japan on November 14 and was quarantined for four days at a facility managed by Vietnam Airlines in HCMC's Tan Binh District.

After two tests showed he was negative for the coronavirus, he was let go but told to isolate himself at home.

Only flight attendants are allowed the short-term quarantine to ensure staff availability for flights.

But during his self-isolation at home, the airline employee came into contact with his mother and two friends, including a Vietnamese man working as an English teacher who came to stay with him for a few days.

On November 29, 15 days after he returned from Japan, he tested positive for the virus, and the next day the English teacher friend too did so. The teacher had meanwhile spread the virus to a nephew and a student of his.

The flight attendant told authorities he had left home on Bach Dang Street in Tan Binh District at noon on November 21 to eat on Le Van Sy Street in Phu Nhuan District.

He then visited Hutech University in Binh Thanh District on November 22.

Phan Ngoc Linh, head of the Vietnam Airlines cabin crew division, has also been suspended for 15 days for letting his subordinate violate quarantine rules.

The carrier on Wednesday also issued a public apology.