Azerbaijan’s President Ilham Aliyev says the Azerbaijani airliner that crashed last week was shot down by Russia, albeit unintentionally.

Azerbaijani authorities investigating last week's Azerbaijan Airlines crash in Kazakhstan are probing the "disturbing" possibility that Russian air traffic controllers may have directed the damaged plane out over the Caspian Sea,

Russia’s failure to let the plane land and its refusal to take responsibility for the crash are upsetting a key partner.

The flight was en route from the Azerbaijani capital of Baku to Grozny, in Russia’s south, when it diverted and attempted an emergency landing in Kazakhstan.

It comes as the head of Russia's civil aviation agency says the situation in Grozny, the plane's destination, was "very complicated" at the time.

Azerbaijan’s President Ilham Aliyev has accused Russia of accidentally shooting down an airliner on Christmas Day in a disaster that killed 38 people, and covering up the cause.