Azerbaijan Airlines, the carrier of the passenger jet that crashed in Kazakhstan on Christmas Day, said preliminary investigations have found the disaster occurred “as a result of physical and technical external interference,

The statement is the closest officials have come to confirming mounting suspicions that the plane was downed by a Russian air-defense system.

An investigation into the deadly crash of an Azerbaijan Airlines flight in Kazakhstan earlier this week came after the passenger plane experienced “physical and technical external interference,” the carrier said Friday.