Azerbaijan on Thursday observed 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.

An Azerbaijani airliner carrying 67 people crashed in southwestern Kazakhstan on Wednesday, killing at least 38 who were on board, according to Kazakh authorities. In a sprawling rescue operation, 29 survivors including two children were pulled from the wreckage near the city of Aktau,

The crash of an Azerbaijani airliner in Kazakhstan has killed 38 of 67 people on board. Azerbaijan Airlines’ Embraer 190 was en route from Azerbaijani capital Baku to the Russian city of Grozny in the North Caucasus on Wednesday when it was diverted for reasons that aren’t fully clear yet.