The cause of the crash of Azerbaijan Airlines flight J2-8243 near the city of Aktau, Kazakhstan, is still unknown. The Kremlin has so far been tight-lipped, prompting questions over its messaging.

By Guy Faulconbridge, Andrew Osborn and Nailia Bagirova MOSCOW/BAKU (Reuters) -President Vladimir Putin on Saturday apologised to Azerbaijan's leader for what the Kremlin called a "tragic incident" over Russia in which an Azerbaijan Airlines plane crashed after Russian air defences were fired against Ukrainian drones.

The White House said Friday there were "early indications" that Russian air defenses downed an Azerbaijan Airlines flight in Kazakhstan.

An Azerbaijan Airlines statement on Dec. 27 blamed “interference” for the Christmas Day plane crash that killed 38 people.

Russia's Vladimir Putin on Saturday apologised to Azerbaijan's president for a "tragic incident" which happened in Russian airspace involving an Azerbaijan Airlines passenger plane that crashed after air defences were used against Ukrainian drones.

The Kremlin has said that the Russian president "apologized for the tragic incident" and expressed his "deep and sincere condolences" to the victims' families.

The plane, which crashed in Kazakhstan this week, went down “due to external physical and technical interference,” according to the investigation’s preliminary findings.

Azerbaijan Airlines says the jet that crashed in Kazakhstan on Christmas Day experienced “physical and technical external interference,” according to an early investigation, as questions swirled about Russia’s possible involvement in the disaster.