Azerbaijan Airlines says the jet that crashed in Kazakhstan on Christmas Day experienced “physical and technical external interference,” according to an early investigation, as questions swirled about Russia’s possible involvement in the disaster.

On 25 December, 38 people died when an Azerbaijan Airlines flight, which had been due to land in Russia, crash-landed in Kazakhstan. The circumstances around the crash remain unclear, but limited evidence so far suggests it may have been damaged by missiles fired by a Russian air-defence system as it tried to land in Chechnya.