Azerbaijan held a day of mourning on Thursday for the dozens of victims of an airliner crash in Kazakhstan, as questions were being asked over the cause of the disaster.

The Azerbaijan Airlines Embraer 190 flight left Baku, Azerbaijan, on Christmas to Grozny, Russia. Instead, the plane crashed in Aktau, Kazakhstan.

NATO on Thursday called for a full investigation into the cause of an Azerbaijan Airlines plane crash that killed 38 people. "Our thoughts and prayers are with the families and victims of Azerbaijan Airlines flight J28243,