Ukrainian airliner
© AFPRescue teams at the site where a Ukrainian airliner crashed in January after being shot down by Iranian defense forces. All 176 people on board the plane died in the incident.
An Iranian military prosecutor says there is no indication that the downing of a Ukrainian passenger jet in Iran in January was due to a cyberattack on the country's defense system.

Speaking on June 29 to some of the families of the victims, Gholam Abbas Torki, the military prosecutor for Tehran Province, reiterated that human error was the cause of the accident that killed all 176 people on board the Boeing 737 airliner.

He said the operator of the air-defense system had not received permission from his superiors before firing two missiles at the airliner.

"Twenty-six seconds passed between the first and second firing, but unfortunately during this time the operator also did not get permission for the second firing from the network," Torki added.

He said three people remain in detention over the downing of the Kyiv-bound aircraft, while three others have been released on bail.

The Islamic Revolutionary Guards Corps (IRGC) took responsibility for the unintentional shooting down of the airliner that came amid heightened tensions with the United States. The incident and the delayed admission of guilt -- it was three days before the IRGC took responsibility -- led to widespread anger and street protests.

Iranian forces had been on high alert at the time of the tragedy, which came hours after Iran launched missile strikes on an Iraqi military base housing U.S. troops. The Iranian strikes were carried out in response to the killing of a top IRGC commander, Qasem Soleimani, in a U.S. drone strike near Baghdad's airport.

Torki defended the delay and said that a preliminary investigation into the incident had been conducted "in the shortest term possible."

He also reiterated that Tehran will send the black box recorders from the plane to France for analysis.

He said the recorders were "physically damaged" and that the data could only be recovered with "sophisticated" technology.