After an Azerbaijan Airlines jet crashed in Kazakhstan, speculation mounted about why the plane went down and whether possible Russian air defense action may have played a role.

Russian aviation authorities said the Azerbaijan Airlines plane had hit a flock of birds. But some experts cast doubt on that account, pointing to footage showing apparent holes in the fuselage.

An Azerbaijan Airlines plane flying from Baku to Grozny that crashed near the city of Aktau in Kazakhstan was shot down by a Russian Pantsir-S air defence system. Source: Reuters, citing its sources Quote: "One of the Azerbaijani sources familiar with Azerbaijan's investigation into the crash told Reuters that preliminary results showed the plane was struck by a Russian Pantsir-S air defence system.