The house was heavily damaged in the fire on August 7
According to a report from Danang Police Department, the fire occurred at around 2 pm at a house on Trung Nu Vuong Street in Hai Chau District.
"A 49-year-old woman and her 14 and 11-year-old sons were found dead inside a bedroom on the second floor," the department said.
A witness who lives some 20 metres from the site said that she heard a loud explosion and came out to see black smoke rising from the second floor of the house.
"A glass window had blown out onto the street following the explosion," the witness said. "Luckily the street was quiet at that time and no one was injured. I and some other people rushed to that house and called at the door but no one answered. We tried to break the locked door but failed and we called the police."
Local people said that the house was also being used to sell votive papers and plastic products.
Police are investigating the cause of the fire.