Russian President Vladimir Putin on Saturday apologized to his Azerbaijani counterpart for what he called a “tragic incident” after an Azerbaijani passenger plane crashed in Kazakhstan, killing 38 people.

The plane was flying from Azerbaijan’s capital Baku to Grozny, the regional capital of the Russian republic of Chechnya, on Wednesday when it veered toward Kazakhstan and crashed while trying to land. 29 of them survived.

In an official statement on Saturday, the Kremlin said air defense systems fired near Grozny on Wednesday in response to a Ukrainian drone attack, but did not say whether one of them had hit the plane.

On Friday, a US official and an Azerbaijani minister issued separate statements blaming foreign weapons for the accident.