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.

Authorities in several countries are working to determine what caused the deadly crash of a passenger plane yesterday in Kazakhstan. Russian aviation officials initially blamed birds, but investigators are now focusing on the possibility that a Russian air defense system struck the plane.