A US official said on Thursday that early indications suggest a Russian anti-aircraft system struck an Azerbaijan Airlines plane that crashed in Kazakhstan, killing 38 people.The comments by the US official, speaking on condition of anonymity, came after media reports that Azerbaijani authorities believe a Russian surface-to-air missile caused Wednesday's crash of the passenger jet traveling from the Azeri capital Baku to Grozny in Chechnya, southern Russia.However the Kremlin Thursday cautioned against "hypotheses" over the crash of the plane that went off course for undetermined reasons.The Embraer 190 aircraft was supposed to fly northwest from Baku to Grozny, but instead diverted far off course across the Caspian Sea.Experts said the plane may have been accidentally shot by Russian air defence systems because it was flying in an area where Ukrainian drone activity had been reported.A former expert at France's BEA air accident investigation agency said there appeared to be "a lot of shrapnel" damage on the wreckage.Several media outlets reported that Azerbaijani authorities believe the crash was caused by a Russian missile.Euronews cited its sources saying the damaged plane "was not allowed to land at any Russian airport despite the pilots' requests for an emergency landing".Page