Early indications suggest a Russian anti-aircraft system may have downed the passenger jet that crashed in Kazakhstan, a US official told CNN, as authorities recovered a second black box that they hope will shed light on the cause of the disaster that killed dozens of people.

Russia’s aviation chief says that a Ukrainian drone attack was under way in the region of Chechnya at the time an Azerbaijani airliner attempted to land before diverting to Kazakhstan and crashing the