Workers and customers were trapped by the blaze that tore through the second floor of the multi-storey building in ThuâÌ£n An city of Binh Duong province on Tuesday around 9pm local time.
The fire quickly spread through the interior woodwork and soundproof foam, forcing revellers in the packed bar to jump from the windows. While some people suffered injuries after jumping from the upper floors, others suffered asphyxiation.
Authorities said there were at least 60 people inside the karaoke parlour when the fire spread.
The blaze was shortly brought under control but smouldered into the next day preventing the rescuers from entering at least one karaoke room and one storage room because of the intense heat.
The victims were identified to be 17 men and 15 women, said Tran Van Chinh, the deputy director of Binh Duong police department.
The search operation was called off after all the bodies were taken to the Thuan An general hospital as hundreds of people crowded outside the building to watch the search.
According to local media, eight people were found dead in the toilet.
Preliminary investigation revealed that the fire may have started from an electrical short circuit on the second or third floor.
Nguyen Sang, who lives near the karaoke bar, said that people tried to escape through the front door as fire tenders made their way to the spot.
“Many people ran outside through the main entrance, but many others could not stand the heat and they jumped down, breaking their hands and legs,” the witness told Vietnam-based VnExpress.
Ho Chi Minh City had reportedly sent 15 elite firemen to assist the rescue operation after the structure of the building collapsed, blocking the pathways.
Duong Ba Khuong, a 27-year-old employee of the parlour, said that the fire spread after an explosion.
“When the fire broke out, I was so panicked and ran for safety and can’t remember how it happened,” a witness, who identified herself only as Quynh, told Vietnam News Agency.
At the hospital, people waited to identify and bring back the charred bodies of their kin.
Nguyen Van Dung tried to reach the karaoke parlour to inquire about his 42-year-old brother who was at the bar when the fire broke out. Mr Dung was informed later in the afternoon that seven people in room 301, including his brother, had died in the blaze.
"He leaves behind his wife and two children," he said.
President Nguyen Xuan Phuc extended his condolences to the victims' families and asked government officials to support them. Meanwhile, prime minister Pham Minh Chinh on Wednesday ordered a further inspection of high-risk venues, including karaoke bars.
Three firefighters died last month while trying to extinguish a fire at another karaoke bar in the capital Hanoi. In 2016, at least 13 people died in another massive blaze at a karaoke lounge in the capital.