Azerbaijan Airlines’ Embraer 190 was en route from Azerbaijani capital of Baku to the Russian city of Grozny in the North Caucasus on Wednesday when it was diverted for reasons that aren’t fully clear yet. It crashed while making an attempt to land in Aktau, Kazakhstan, after flying east across the Caspian Sea.

Thirty-eight of 67 onboard flight from Baku to the Chechen city Grozny believed to have been killed. Russian authorities cite bird strike.

Mobile phone footage circulating online appeared to show the Azerbaijani Airlines plane making a steep descent before slamming into the ground in a fireball in western Kazakhstan.