The Embraer 190 was traveling to Grozny, Russia, but crashed near Aktau, Kazakhstan, killing 38 people onboard. Investigators are focusing on Russian air defense as the likely cause.

A passenger jet operated by Azerbaijan Airlines crashed near the city of Aktau in Kazakhstan on Wednesday, after diverting from an area of southern Russia where Moscow has repeatedly used air defence systems against Ukrainian attack drones.

The plane, which crashed in Kazakhstan this week, went down “due to external physical and technical interference,” according to the investigation’s preliminary findings.