The aircraft involved in the Christmas Day plane crash in Kazakhstan that killed 38 people experienced “external physical and technical interference”, according to preliminary results of an investigation, Azerbaijan Airlines said on Friday. The early findings led the carrier to suspend flights to five Russian airports, citing “potential risks to flight safety”, adding to the two routes that were suspended immediately after the crash. The plane was flying from the Azerbaijani capital, Baku, to the Russian city of Grozny in Chechnya when it crashed in a field near Aktau in Kazakhstan, hundreds of miles off its planned route. Twenty-nine people survived. On Friday, the head of Russia’s civil aviation agency said that the aircraft had tried to land in Grozny as the region was under attack by Ukrainian drones. Ukrainian military drones were carrying out terrorist attacks on civilian infrastructure … at the time,” Dmitry Yadrov said on Telegram, adding that the plane had made two unsuccessful attempts to land. At the time there was also heavy fog over Grozny, he said. He described the conditions as “very complicated”. He added: “The pilot was offered alternative airports. He took the decision to go to Aktau airport.” As hospitals scrambled to treat the dozens of injured passengers and Azerbaijan mourned those who lost their lives, speculation has swirled about the cause of the crash. A US official said on Thursday that there were early indications that a Russian anti-aircraft system may have struck the plane, echoing claims by Ukrainian officials and sources in Azerbaijan. eople lay flowers in memory of the victims of the Azerbaijan Airlines crash at an airport outside Baku. Photograph: EPA On Friday, the Kremlin’s spokesperson, Dmitry Peskov, declined to comment on the claims. “The air incident is being investigated and we don’t believe we have the right to make any assessments until the conclusions are made as a result of the investigation,” he told reporters. Images of the crash appeared to show the plane plummeting to the ground where it burst into flames on impact, giving rise to thick, black plumes of smoke.