Authorities in Kazakhstan are investigating the cause of an Azerbaijan Airlines plane crash in the country, which killed 38 people and injured 29 others on Christmas Day.The big picture: Flight J2-8243 was diverted while en route from Baku,

The leader of Azerbaijan criticized the Russian response to the crash of a passenger jet that Azerbaijani officials said had most likely been hit by Russian air defenses.

Russian President Vladimir Putin apologized for the “tragic incident,” which left 38 people dead, though he stopped short of taking responsibility.

Several passenger plane crashes have occurred worldwide this year, including a Wednesday morning Azerbaijan Airlines wreck that has left dozens feared dead.

T hursday is an official day of mourning in Azerbaijan as an investigation is underway to determine what caused an airplane carrying 67 passengers to crash on Christmas Day in Kazakhstan, killing 38 and leaving at least 29 survivors. Video posted by CNN shows the plane crash-landing, exploding into a fireball and plumes of black smoke.

"We can clearly say today that the plane was shot down by Russia," President Ilham Aliyev said in a televised statement

Four sources with knowledge of the preliminary findings of Azerbaijan's investigation told Reuters that Russian air defences mistakenly shot it down.

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.