Russia’s President Vladimir Putin has apologized for the fact that an Azerbaijan Airlines flight crashed after entering Russian airspace in Grozny, Chechnya on Wednesday, but did not say that Russia was responsible.

Azerbaijan Airlines plane crash, likely caused by Russian air defense, shines light on a glaring issue the Kremlin has long swept under the rug.

Russian President Vladimir Putin apologized for the deadly Azerbaijan Airlines Flight 8243 crash on Christmas but did not take responsibility for causing it as an investigation continues into the matter.