President Hassan Rouhani said an investigation found that “missiles fired due to human error”, described the crash as an “unforgivable mistake”. Iran’s Revolutionary Guards apparently mistook it for a hostile aircraft, despite all passenger jets having active transponders, broadcasting their position, that radar tracking would have shown the passenger jet leaving Tehran Airport, not entering Iranian airspace. This mistake takes a lot of incompetence to achieve.
In an another statement, Iran’s General Staff of the Armed Forces took responsibility, called it a “human error” and apologised for mistakenly shooting the plane by IRGC forces. 176 innocent people lost their lives.