A police source said sparks coming from the muzzle of a gun might have reached residual gunpowder on the floor or flammable dust in the air. Sparks from the gun might have ignited by combining with gas and gunpowder in the air.

Given that a body with shooting earplugs was found on the floor, the fire could have erupted when guns were being fired.

Another possibility is sparks resulting from the overheating of electric motors designed to move shooting targets. The shooting range had used two electric motors since three others were out of order.

“The victims could not escape from the range due to the explosion and flames. Considering this, the likelihood that a backdraft occurred is high. Against this backdrop, we’re trying to find the material that initially caused the fire. If the National Institute of Scientific Investigation releases its preliminary results next week, our investigation will accelerate,” a police source said.

Via a Korean Air flight, the bodies of seven Japanese victims were flown to Fukuoka from Gimhae International Airport at 5:50 p.m. yesterday. Their relatives prayed for the victims at a simple funeral ceremony at 2 p.m., which was held at Pusan National University Yangsan Hospital in Yangsan, South Gyeongsang Province.