The explosion occurred at 4:30 p.m. on Saturday and caused the mall's ceiling and walls to collapse. The blast triggered panic as workers and visitors assumed it had come from a bomb.

Depok Police chief Comr. Imran Edwin Siregar later confirmed that an elevator had fallen.

“I say it once again — there was no bomb. Gegana [police bomb squad] has checked the area and there was no bomb,” Imran said in a statement on Saturday.

The Depok Police forensics laboratory concluded that a gas leak had triggered a blast, which subsequently caused a freight elevator to fall from the third floor due to its heavy load and the building's fragile structure.

One person, a coffee shop employee, later died in the hospital early on Sunday after sustaining head injuries from falling debris. Ten others were injured, including mall employees, security guards and visitors, according to the police. Most of the injured were treated at the Bunda General Hospital and some at the University of Indonesia’s (UI) hospital.

“Of 11 victims, one died. Two [injured people] have been sent home,” Imran said on Sunday morning.

Bunda hospital director Imelda Rahmawati told tempo.co that four people had suffered serious injuries, with severe burns in the face and arms, while three others who had been hit by a collapsed ceiling were waiting for CT scan results as of Sunday afternoon.

Police said they will continue to investigate the cause of the gas leak, and the mall will be closed until further notice.

"This [the gas leak] is still being investigated by the forensic laboratory," Imran said. “Further developments will probably be announced tomorrow [Monday].”