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.

Azerbaijan Airlines crash: was this another military shoot-down of a civil aircraft? - Key questions and answers about the first fatal crash anywhere in the world involving a passenger jet in 2024

Putin apologized for the “tragic incident” that occurred in Russian airspace, but the Kremlin did not take responsibility for downing the Azerbaijan Airlines flight.

The Azerbaijan Airlines plane flew hundreds of miles off its scheduled route from Baku to Grozny, and crashed on the eastern shore of the Caspian Sea. Russia's aviation watchdog said a bird strike might have been the cause.

Sources told Reuters the plane had been hit by Russian fire. "It was as if it was drunk - not the same plane anymore," one passenger recalled.

A passenger jet operated by Azerbaijan Airlines crashed near the city of Aktau in Kazakhstan on Wednesday, after diverting from an area of southern Russia where Moscow has repeatedly used air defence systems against Ukrainian attack drones.