The women, aged between 21 and 30, were transferred to the National Hospital of Tropical Diseases in Hanoi.
Two of them showed positive results for the second time while the remaining four tested positive for the coronavirus for the first time and are awaiting their second results, Pham Ngoc Thach, director of the National Hospital of Tropical Diseases, told VnExpress .
These cases have yet to be confirmed by the Health Ministry.
Epidemiological investigation showed the group of women working at Sunny Dong Son bar in Phuc Yen Town of northern Vinh Phuc Province previously came in contact with five Chinese experts of Trung Bac A Minerals JSC.
After entering Vietnam, the Chinese experts were sent to Nhu Nguyet 2 hotel in Yen Bai Town for 14-day centralized quarantine from April 9 to 23. They had their samples taken for coronavirus testing thrice, with all results negative.
After completing their centralized quarantine period, the group was handed to Trung Bac A Company and continued to have their health monitored for 14 days at Bao Yen Hotel in Nghia Lo Town, Yen Bai Province under supervision of local medical staff.
Vu Hien Hanh, vice chairwoman of Yen Bai, said the experts had voluntarily left their hotel and visited many localities like Sa Pa Town of Lao Cai Province, Binh Xuyen District of Vinh Phuc Province, Phong Tho and Tan Uyen districts of Lai Chau Province, and Van Chan District of Yen Bai, all in northern Vietnam, from April 23 to 25.
On April 28, they returned to China through Huu Nghi border gate in Lang Son Province. A day later, one of the five experts was confirmed positive for the virus by Chinese authorities.
Vinh Phuc on Saturday ordered the closure of bars, dance clubs, karaokes, massage parlors and entertainment venues.
Those traveling on flight VN7161 that departed Hanoi at 2:20 p.m. to arrive in Da Nang at 3:46 p.m. on April 27, and flight VN160 departing Da Nang at 10:46 a.m and landing in Hanoi at 12:10 p.m. on April 29 need to contact medical centers as soon as possible, the health ministry stated.
After over a month without new community transmission cases, 16 have been confirmed by the health ministry since Thursday in four localities including ten in northern Ha Nam Province, three in Hanoi, two in northern Hung Yen Province, and one in Ho Chi Minh City, all linked to a Ha Nam man who returned from Japan and tested positive two days after completing two-week quarantine.