The extremely rare publicised apology from Putin was the closest Moscow had come to accepting some blame for Wednesday's disaster, although the Kremlin statement did not say Russia had shot down the plane.

Azerbaijan Airlines plane crash, likely caused by Russian air defense, shines light on a glaring issue the Kremlin has long swept under the rug.

On 25 December, 38 people died when an Azerbaijan Airlines flight, which had been due to land in Russia, crash-landed in Kazakhstan. The circumstances around the crash remain unclear, but limited evidence so far suggests it may have been hit by missiles fired by a Russian air-defence system as it tried to land in Chechnya.