Drone crash: unconventional explosive used in bomb, investigators say

Investigators have concluded that a military drone that crashed in Zagreb on March 10 was armed with bomb containing an “unconventional” type of explosive.

Prosecutors and military and forensic experts presented their findings at a news conference on Wednesday, however, their conclusions left many questions about the drone crash unanswered.

Members of the investigative team said the Soviet-era surveillance drone had been armed with a bomb but the explosive that was used was neither military nor commercial. They described it as an "unconventional substance" that disintegrated upon impact, making it impossible to identify.

Maj. Mile Tomić said 47 metal fragments belonging to the device were found at the crash site indicating an explosion had occurred. Experts have even identified the type of aerial bomb that was used, an OFAB 100-120 air bomb. However, it appears bomb was altered and filled with an unconventional type of explosive, according to Ivana Bačić, a fire and explosives expert.

"Most likely, this was a high-energy but unconventional substance or a composite of organic substances that completely disintegrated in the explosion, making it impossible to identify," said Bačić.

Col. Mario Počinok, a military aircraft expert, said the drone crashed due to a malfunction in the automatic landing system.

"Therefore, the drone, at high altitude, discarded its main parachute, and continued in free-fall until it hit the ground,” Počinok said.

The team believes the drone was meant to be used as a lethal weapon because of the fact that a surveillance drone would not be armed.

The County Prosecutor's Office in Zagreb is treating the case as a serious crime that threatened public safety.

The drone apparently flew from Ukraine over Romania and Hungary before crossing into Croatia and crashing near a student dormitory in Zagreb's Jarun Lake neighborhood. The crash damaged dozens of cars but no one was injured.

Investigators still do not know who sent the drone or why. County Prosecutor Jurica Ilić said the drone had markings in gray, white, red, blue, and yellow, indicating the drone could be Russian or Ukrainian.

"It is difficult to determine who repurposed the drone, who altered the bomb, and why. When we know who did it, we might get the answer as to why they did it,” Ilić said.

Both Russia and Ukraine have denied launching the aircraft.