The preliminary results of Azerbaijan’s investigation into the deadly crash of a civilian airliner point to the plane being hit by a Russian antiaircraft missile, or shrapnel from it, said people briefed on the probe.

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.

Aviation experts said Thursday that Russian air defense fire was likely responsible for the Azerbaijani plane crash the day before that killed 38 people and left all 29 survivors injured.