MINNEAPOLIS — Fire officials said Monday they could not determine the exact cause of a high-rise apartment fire that killed five people last week in Minneapolis and that a handful of factors may have contributed to igniting the blaze.

The Minneapolis Fire Department said Wednesday’s fire was accidental, originating in a bedroom wall in a unit on the 14th floor.

A fire incident report released Monday says electrical factors could have contributed to the blaze. But Assistant Chief Bryan Tyner said there were other possible factors, such as smoking materials and a baseboard heater.

“Each of those could’ve led to the fire,” Tyner said. “They are sure it was an accidental cause, but they can’t narrow down or say exactly what the cause was.”

The report says the heat source, an item that first ignited and the type of material that was first ignited are all “undetermined.” The cause is listed as “unintentional” and the report says there were no human factors that contributed.

State Rep. Mohamud Noor, who represents the predominantly immigrant neighborhood where the fire happened, said the report gives him some reassurance that authorities conducted a thorough investigation.

“It’s a little bit comforting, but at the same time, this was a tragic incident that took place,” he said.

The apartment building is 50 years old and was not required to have sprinklers due to its age. Noor said he is working on legislation that would require the retrofitting of most high-rise buildings to include sprinkler systems.

“That is something that we should have done a long time ago,” he said.

The State Fire Marshal Division estimates that fewer than 10 percent of the apartments in Minnesota are protected with fire sprinklers. There were no state requirements for sprinkler systems in high-rise buildings until the 1979 Uniform Building Code took effect in late 1980. Building code requirements apply to new construction and are not retroactive for existing buildings.

The victims in the fire have been identified as Tyler Baron, 32; Jerome Stewart, 59; Nadifa Mohamud, 67; Maryan Mohamed Mohamud, 69; and Amatalah Adam, 78. All five died from smoke inhalation. Three others were injured.

According to the fire incident report, crews were on the scene less than four minutes after the fire was called in by the alarm company. The report says combination smoke and heat detectors were operating, and the fire was contained to the unit where it started and the hallway.

One victim was found as firefighters were attacking the fire. Another was found outside the “fire room,” the report said. Two more victims were found in two different adjacent apartments on the 14th floor, and a fifth victim was found in the stairwell by the 17th floor.

The public housing complex that includes this building was scheduled for a routine inspection by the U.S. Department of Housing and Urban Development on Monday. But HUD said Monday that the inspection is being rescheduled.