Investigators into the crash of an Azerbaijan Airlines plane in Kazakhstan that killed 38 people are trying to determine what caused the aircraft to divert from its planned landing in Grozny, the capital of Russia-controlled Chechnya.

The Embraer 190 passenger plane, which was carrying 62 passengers and five crewmembers, crashed on Wednesday three kilometers from the airport at Aktau, a city on the Caspian Sea in southwestern Kazakhstan. The plane had been heading from the Azerbaijani capital of Baku to Grozny, but eventually declared an emergency and headed to Aktau, about 440 kilometers to the east and across the Caspian, for reasons that have yet to be clarified.

“Even a preliminary cause cannot be established because there are specialists for that. They will carry out their work. Only after that it will be clear. I can’t say anything at this point,” said Kazakh Deputy Prime Minister Kanat Bozumbayev, according to the state Kazinform news agency. “I saw what people posted… While it was falling to the ground, it was flipping over, many things could have happened. Therefore, I am far from making any conclusions.”

Russia’s state-run news agency Tass initially reported that fog in Grozny caused Flight J28243 to divert to Makhachkala, the capital of the Russian territory of Dagestan, and then to Aktau. RIA Novosti, another Russian state-owned media outlet, cited Russian aviation authorities as saying the plane diverted because of a collision with birds.

However, some aviation and military analysts have paid particular attention to a video showing numerous small holes on part of the fuselage wreckage, and there is speculation that air defense systems may have fired on the plane; Chechen officials have reported shooting down drones from Ukraine, which is at war with Russia. Bozumbayev, the Kazakh minister, was asked about the possibility that the aircraft was fired on, and said that final results of the investigation will be announced after all evidence is examined, reported the Azeri Press Agency, or APA.

The prosecutor general’s office in Kazakhstan has opened a criminal case and the country’s chief transport prosecutor visited the scene as a member of a government commission. Kazakh media reported that the flight recorder had been found.

Video and images released by Kazakhstan’s Ministry of Emergency Situations showed rescue teams converging in vehicles and on foot on the flaming plane wreckage in a flat expanse of land near Aktau. One vehicle trained a water hose on the flames. Debris from the plane was scattered in the area.

Emergency responders were able to pull survivors from the crumpled, partly intact fuselage. Some video appearing on social media showed a survivor limping out of the wreckage while another passenger who had been rescued was unable to walk because of apparent leg injuries. Another unverified video also shows a passenger purportedly praying on the plane in the minutes before the crash.

News of the crash came as Russian President Vladimir Putin hosted a meeting in St. Petersburg for leaders of the Commonwealth of Independent States, a regional group that includes the post-Soviet states of Belarus, Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan and Turkmenistan.

A Russian government aircraft will deliver medical personal and equipment to Aktau, in coordination with Kazakh authorities, Putin said at the beginning of the meeting. He said he had spoken to Aliyev, who was flying to the St. Petersburg meeting at the time but returned to Baku after learning about the Aktau crash, and that Russia will assist with the investigation.

In a message to Aliyev, Kazakh President Kassym-Jomart Tokayev expressed condolences and said his government had established a panel to provide “the necessary assistance” to Azerbaijan.

Azerbaijan Airlines and the country’s emergency ministry said in a joint statement that the bodies of Azerbaijani citizens who died in the crash will soon be transported back to Azerbaijan, and that a flight will also be arranged for injured passengers if doctors allow them to travel.

The airline also said that, while the investigation of the crash is underway, it had suspended flights to and from Grozny as well as Makhachkala, the nearby capital of Russia-controlled Dagestan.

There were 62 passengers on the flight, including 37 people from Azerbaijan, 16 from Russia, six from Kazakhstan and three from Kyrgyzstan, according to the airline. There were five crewmembers. Of the 67 in total on the plane, 38 died, according to Kazakh officials.

Kazakhstan’s Ministry of Emergency Situations said the other 29 people, including two children, were hospitalized, including 15 from Azerbaijan, nine from Russia and three from Kyrgyzstan. It said the nationalities of two injured people were being determined. The six Kazakh passengers on board the plane died, the ministry said.