Under the ministry's new decision, high school seniors from localities not constrained by the social distancing order would take the exams on August 9-10 as planned, while those who are quarantined or living in locked down areas can sit for it later.

"Most localities are ready for the upcoming national high school exams and the education ministry will work closely with health experts to ensure safety for all students," said Phung Xuan Nha, Minister of Education and Training.

Around 900,000 high school seniors in the country are expected to take the two-day exam this Sunday. This exam is seen as a seminal event in the country, with success or failure having far-reaching impacts. The exams not only award a high-school certificate, but also decide admissions to universities and colleges.

The new wave of community transmission of the novel coronavirus infections had worried many 12th-graders in pandemic hit localities like Da Nang and Quang Nam.

Nguyen Truong Hieu, a 12th grader at Phan Chau Trinh School in Da Nang, Vietnam's biggest Covid-19 hotspot now, said he had been stressed out for a week after "Patient 416", a 57-year-old man, was confirmed infected on July 25, ending Vietnam's 99-day streak without community transmission.

"What worried me the most was the possible lack of safety when taking the exam, despite the distance maintained. It is hot and wearing a mask for several hours while doing the test would be very uncomfortable," Hieu said.

Da Nang, which has recorded 135 cases, began 15-day social distancing July 28, requiring people to stay at home and maintaining a distance of at least two meters from each other in public. Public gatherings of more than two people are prohibited, except at offices, schools and hospitals.

The government admitted Sunday it has been unable to find the origin of the outbreak in Da Nang, a popular tourism hotspot with a population of 1.1 million people.

Quang Nam, which neighbors Da Nang, is also a new Covid-19 epicenter with 41 cases and many parts of the province were locked down to prevent the spread of the coronavirus.

Vietnam has recorded 642 cases of Covid -19 so far, including 262 active patients. Six people have died.

Thousands of high school seniors only returned to school in March after a prolonged break since the Lunar New Year in January when schools remained closed to curb the spread of the coronavirus.