Azerbaijan is observing a nationwide day of mourning for the victims of the air crash that killed 38 people and left all 29 survivors injured as speculation mounted about a possible cause of the crash that remained unknown.

Azerbaijan Airlines' Embraer 190 was en route from the capital of Baku to Russian city of Grozny in the North Caucasus when it was diverted for reasons yet unclear and crashed while making an attempt to land in Aktau after flying east across Caspian Sea

Azerbaijan mourns air crash victims as speculation grows on cause, with theories including possible drone attack.

Azerbaijan is observing a nationwide day of mourning for the victims of the air crash that killed 38 people and left all 29 survivors injured as speculation mounted about a possible cause of the crash that remained unknown.