Of the 28 new cases, 20 are from Danang hospitals, six from local community transmissions in Danang and two Vietnamese citizens returning from Indonesia.

Vietnam had been seen as a global success story in combating the coronavirus, with no deaths and no confirmed cases of local transmission for 99 days.

But a week ago, an outbreak began at a Danang hospital.

It has spread to six parts of the country, including three of the largest cities, forcing authorities to reimpose virus restrictions.

Danang is Vietnam's most popular beach destination and thousands of visitors were in the city for summer holidays.

Across the country, authorities are rushing to test people who have returned home from the coastal city.

Both men died in a hospital in Danang.

The Health Ministry said a 61 year-old man died on Friday evening of septic shock and chronic kidney failure.

The country's first fatality was a 70-year-old man who was being treated for a kidney illness.

Fifteen other patients with COVID-19 are in critical condition, officials said.

All have other underlying illnesses.

Experts worry the actual number of cases could be far higher.

Before the latest outbreak Vietnam had a total of only 416 cases.

In the capital Hanoi, where two people have tested positive after returning from Danang, more than 100 clinics have been set up with test kits to detect the virus.

Australian Associated Press