Two cases were confirmed by the Ministry of Health on May 5 and they are in quarantine at the National Hospital for Tropical Diseases No2 for medical surveillance and treatment.
Nine more cases were announced on May 6 by the provincial Department of Health.
The newly-detected patients are now receiving treatment at the provincial General Hospital.
Relevant agencies have identified and isolated nearly 3,000 people who had direct or indirect contact with COVID-19 patients. Swift contact tracing is underway in all localities.
Local authorities also moved to temporarily close non-essential services such as restaurants, coffee shops, bars, cinemas, massage parlors, as well as many cultural and sporting events of large gatherings.
They advised local people to strictly follow the Ministry of Health’s COVID-19 rules, including the 5K message in Vietnamese, namely Khau trang (face mask), Khu khuan (disinfection), Khoang cach (distance), Khong tu tap (no gathering), and Khai bao y te (health declaration).