Azerbaijan on Thursday observed a nationwide day of mourning for the victims of the plane crash that killed 38 people and left all 29 survivors injured as speculation mounted about a possible cause of the disaster,

The Kremlin warns against premature conclusions, as reports mount that its air defenses misidentified the airliner as a Ukrainian drone

Kazakh authorities have recovered the flight data recorder and an investigation is under way. Shortly after the crash, reports from Russian state-controlled TV said the most likely cause was a strike from a flock of birds.