"At around 1:00 or so, there were one or two slight, minor explosions, and it wasn't until around 2:40 or so that a second major blast occurred," one resident said.

The fire reportedly broke out shortly after 01:00 in Annan District, with a major explosion occurring around 02:45 as firefighters battled the blaze.

Authorities said the site contained industrial waste, including discarded oil barrels and materials containing aluminium and magnesium. The cause remains under investigation.

"The preliminary findings... confirmed that there were discarded oil barrels inside, as well as scrap aluminium and magnesium," Tainan Fire Department director Yang Zonglin said. Fifteen people were injured, including three firefighters, although none sustained life-threatening injuries.

At least 68 homes were affected, including 11 directly damaged by fire, while more than 20 civilian and emergency vehicles were also damaged. Authorities deployed 144 firefighters and 53 vehicles to the scene.

"Earlier, at around 10 am, I was looking from the street, and I saw what looked like orange flames on the top floor of this building," one resident said.

Another witness described seeing the fire intensify as debris began falling.

"What I saw was that the fire had started to die down; it suddenly grew larger from inside this side of the building. Some debris fell from above. I think the fire may have weakened the structure, causing some of the debris to fall," the resident said.

The fire spread from the 11th to the 16th floors, according to Jakarta authorities. Strong winds complicated firefighting efforts and caused the flames to flare up again.

A renovation worker trapped on the 15th floor was rescued and taken to Tarakan Regional General Hospital for treatment. No deaths were reported.

Jakarta's fire and rescue service initially deployed 37 fire units and 185 personnel, supported by three Bronto Skylift aerial vehicles. A later update increased the response to 40 units and 200 personnel.

The fire was brought under control after roughly four hours of firefighting. Crews then carried out cooling operations and inspections for remaining hotspots.