Azerbaijan’s flag carrier has announced the suspension of flights to several Russian airports, citing potential flight safety risks following a crash of one of its planes that many experts have blamed on Russian air defense fire.

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.

An Azerbaijan Airlines flight that crashed in Kazakhstan on Wednesday was downed by a Russian air defence system, four sources in Azerbaijan with knowledge of the investigation told Reuters. An Embraer passenger jet crashed near the city of Aktau in Kazakhstan on Wednesday,