Azerbaijan’s leader on Monday accused Moscow of carrying out a “cover up” over a passenger jet crash last month that claimed 38 lives, as relations sour between the two neighbors.

Russian President Vladimir Putin apologized for the plane crash in Russian air space on Christmas Day that left 38 people dead in a statement that said Russia was targeting Ukrainian drones over the plane’s planned destination at the time, but stopped short of taking responsibility.

Azerbaijan President Ilham Aliyev said Russia is behind the Christmas Day crash of an Azerbaijan Airlines plane in Kazakhstan, which killed 38 of the 67 people aboard. The motives of the incident remain unclear.

Azerbaijani President Ilham Aliyev blasted Russia for putting forward “absurd” theories initially and said Moscow must compensate victims’ families.

Azerbaijan’s President Ilham Aliyev added that it was unintentional but criticised Moscow for trying to “hush up” the shooting for days.View on euronews

In the crash’s aftermath, Azerbaijan has unleashed rare and stinging criticism of Russia, with the country’s president saying Moscow’s response has caused “surprise, regret and rightful indignation.”

Azerbaijan's president said on Monday that Russia was "guilty" over the downing of an airline last month that Baku says was shot by Russian air defenses. An Azerbaijan Airlines Embraer 190 jet crash-landed in Kazakhstan on Dec.