Russia's leader apologises over the downing of an Azerbaijani plane in Russian airspace - without directly taking blame.

In a phone call, Russian President Vladimir Putin apologized to the president of Azerbaijan, saying the "tragic incident occurred in Russia's airspace." Putin did not say Russia was responsible for the attack that killed 38 of the 67 people onboard.

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