Witnesses told authorities the fire started at around 1 a.m. on the second floor of the three-story building as hundreds of people were singing in private rooms at the Inul Vizta Karaoke club in downtown Manado, the capital of North Sulawesi province, said the city police chief Col. Rio Permana. Workers were unable to put out fires with extinguishers.

Many complained that fire engines arriving late, about an hour later. It took firefighters several hours to bring the blaze under control.

"We are still investigating the cause of fire," Pernama said, but a preliminary investigation indicated a short circuit.

He said some panicked people smashed windows and fled into the street while many others were stuck in choking black smoke billowing from the second floor as there was only one access door to the building.

All 17 people who died were Indonesians. Most died from smoke inhalation injuries rather than burns, Permana said.