HANOI, Vietnam (AP) — Vietnam reported more than two dozen new cases of the coronavirus on Saturday, while a third person died of COVID-19 complications a day after the country reported its first-ever death from the disease.

Vietnam had been seen as a global success story in combating the coronavirus, with no confirmed cases of local transmission for 99 days. But a week ago, an outbreak began at a Da Nang hospital. It has spread to six parts of the country, including three of the largest cities, forcing authorities to reimpose virus restrictions.

Da Nang is Vietnam’s most popular beach destination, and thousands of visitors were in the city for summer vacation. Across the country, authorities are rushing to test people who have returned home from the coastal city.

Of the 28 new cases reported Saturday, 20 are from Da Nang hospitals and six are from local community transmissions in the city. The other two are Vietnamese nationals returning from Indonesia.

The Health Ministry said the latest fatalities included a 68-year-old woman who was treated for blood cancer and a 61-year-old man who suffered septic shock and chronic kidney failure. The country’s first COVID-19 death was a 70-year-old man who was admitted with a kidney illness.

All three died in a hospital in Da Nang.

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 Hanoi, the capital, where two people have tested positive after returning from Da Nang, over 100 clinics have been set up with test kits to detect the virus. Hanoi has tested a third of the 54,000 people returning from Da Nang.

In Ho Chi Minh City, the country’s southern hub, five people who returned from Da Nang have tested positive for the virus. The city is testing some 20,000 other returnees.

“The COVID-19 outbreak is no longer an issue in Da Nang only when we have recorded cases in Quang Nam, Hanoi, Ho Chi Minh City among other locations,” acting health minister Nguyen Thanh Long said.

As the number of case continues to increase, Da Nang has tightened security and set up more checkpoints to prevent people from leaving or entering the city, which has been in lockdown since Tuesday.

The city on Friday began setting up a makeshift hospital in a sports auditorium and doctors have been mobilized from other cities to help.

Hoi An, an ancient town and top tourist destination known for its charming old houses 20 kilometers (12 miles) south of Da Nang, stopped allowing visitors on Thursday because of the outbreak. Its pedestrian streets, adorned with lanterns, were empty and nonessential services and gatherings were banned.

This story has been corrected to show that three people in Vietnam have died from the coronavirus, not two.