A criminal investigation was under way into the passenger plane crash early on Wednesday in Kazakhstan, killing at least 38 people, Azerbaijan’s leader said.View on euronews

The Kremlin on Thursday called for restraint after reports emerged that a Russian air defense system could have brought down an Azerbaijan Airlines passenger jet. The plane, an Embraer 190, was traveling from Baku to Grozny in southern Russia when it crashed on the shore of the Caspian Sea in Kazakhstan on Wednesday.

Thursday is an official day of mourning in Azerbaijan as an investigation is underway to determine what caused an airplane carrying 67 passengers to crash on Christmas Day in Kazakhstan, killing 38 and leaving at least 29 survivors.

Russia and Kazakhstan have tried to calm speculation about the cause of the Azerbaijan Airlines plane crash, following claims that it was shot down by Russian air defence systems.On Thursday, Moscow urged calm as its foreign minister said it would be wrong to draw conclusions before an investigation into the crash was complete.

Officials in Russia and Kazakhstan are urging people to wait for an investigation into the deadly Azerbaijan Airlines plane crash before assigning blame.

Russian President Vladimir Putin has expressed his condolences to Ilham Aliyev, the president of Azerbaijan, over the loss of life on Wednesday in a plane crash involving an Azerbaijan Airlines plane,