Investigators have determined that two Tor-M1 robots were fired at the plane, according to a preliminary report published on the Iranian Aviation Authority's website. It reports German Deutsche Welle, who adds that the investigation is still ongoing.
The statement appears to confirm the information already reported by The New York Times. The American newspaper already reported a week ago that two robots were fired, at about 30 seconds apart.
The anti-aircraft robots are a model of short-range robots developed by the Soviet Union to shoot down aircraft or cruise missiles.
Flight PS752 crashed soon after departing from the Iranian capital Tehran, heading for the Ukrainian capital Kiev. On board, there were 167 passengers and nine from the crew, according to official data. 17 of those who died in the crash were native to Sweden.
Iranian authorities initially stated that the aircraft had engine problems, but then acknowledged that the plane had been accidentally shot down. The passenger aircraft is to be perceived as a "hostile target" in the cramped position vis-à-vis the United States, according to Iran.