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.

Four sources with knowledge of the preliminary findings of Azerbaijan's investigation told Reuters that Russian air defences mistakenly shot it down.

As many as 38 people died in a horrific crash of an Azerbaijan Airlines plane near the Aktau city in Kazakhstan earlier this week. The flight, J2-8243, carrying 62 passengers and five crew members, was supposed to fly from Baku to Grozny in Russia's Chechnya.