The Azerbaijan Airlines plane flew hundreds of miles off its scheduled route from Baku to Grozny, and crashed on the eastern shore of the Caspian Sea. Russia's aviation watchdog said a bird strike might have been the cause.

Azerbaijan Airlines’ Embraer 190 was en route from Baku to the Russian city of Grozny when it was diverted for reasons yet unclear and crashed while making an attempt to land in Aktau in Kazakhstan.

Early indications suggest a Russian anti-aircraft system may have downed the passenger jet that crashed in Kazakhstan on Wednesday, a US official told CNN as Azerbaijan held a day of mourning for the dozens of victims of the disaster.

Azerbaijan Airlines’ Embraer SA 190 aircraft was damaged by Russian air defense systems near Grozny before it crashed in Kazakhstan during an attempted emergency landing, according to Azerbaijan government-backed Caliber news website.

Russian air defenses downed an Azerbaijan Airlines plane that crashed in Kazakhstan, killing 38 people, four sources with knowledge of the preliminary findings of Azerbaijan's investigation into the disaster told Reuters on Thursday.

At least 38 people were killed in an Azerbaijan Airlines crash that was likely caused by Russian antiaircraft fire, according to Ukraine and aviation experts. Photo: Azamat Sarsenbayev/Reuters