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 said Putin had "offered his apologies that the tragic incident had occurred in Russia's airspace."

Vladimir Putin admitted Saturday Russian air defence was working when an Azerbaijani Airlines plane tried to land in Grozny before crashing, breaking the Kremlin's silence as speculation mounted Russia may have accidentally shot the plane.