Azerbaijan Airlines said Friday the passenger jet that crashed in Kazakhstan on Christmas Day experienced “physical and technical external interference,” according to an early investigation. At least 38 of the 67 people on board the plane were killed in the crash,

Experts say evidence in the Azerbaijan Airlines plane crash in Kazakhstan points to a possible midair explosion, not an encounter with a flock of birds.

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.