Experts say evidence in the Azerbaijan Airlines plane crash in Kazakhstan points to a possible midair explosion, not an encounter with a flock of birds.

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.