Azerbaijan Airlines’ Embraer 190 was en route from the Azerbaijani capital of Baku to Grozny in the North Caucasus on Wednesday when it was diverted. It crashed while trying to land near the city of Aktau, Kazakhstan, after flying hundreds of kilometers (miles) east across the Caspian Sea.

On Christmas Day, a plane traveling from Baku, Azerbaijan, to Grozny, Russia, crashed in Kazakhstan, killing over half of its passengers. Theories abound regarding why the plane made an emergency landing near the Kazakhstani city of Aktau.

In a Dec. 27 phone conversation with Aliyev, Kazakh President Kasym-Jomart Tokayev discussed the progress of work of the special state commission to investigate the crash and assured that the Kazakh side will make every effort to ensure comprehensive and objective clarification of all circumstances of the crash.