The Kremlin urged restraint on Thursday in speculating about the cause of an Azerbaijan Airlines plane crash in Kazakhstan that killed 38 of the 67 passengers on board. "An investigation is currently under way;

Following the crash of a passenger plane in Kazakhstan, Moscow is cautioning against speculation that the aircraft may have been shot down, killing 38 people of the 67 people on board. "An investigation is currently under way;

After 38 people died in the crash, some experts said the plane may have been accidentally shot by Russian air defense systems in an area where Ukrainian drone activity had been reported.

An Azerbaijani airliner has crashed in Kazakhstan after being diverted, killing 38 of 67 people on board. Some things to know about the crash and the speculation about a possible cause: How did the plane crash?

Rescue teams are searching for survivors after a passenger plane crashed in Kazakhstan. Fox - 32 Chicago Fox - 32 Chicago. More Videos

Even as a probe was starting of the crash of an Azerbaijan Airlines airliner in Kazakhstan, speculation was mounting about why the plane went down.

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

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.