Center Marcin Gortat said Thursday after practice that there was "one gentleman who really threatened us, actually made some terrorist threats to us."
Gortat, who is from Poland, said that "he was saying there was a bomb on the plane and stuff, that my country's going to get bombed and all my family's going to die, just stuff like that."
The tweets came after the Wizards' Game 2 win in Chicago last week.
Wizards spokesman Scott Hall said the matter was turned over to the league. Added Gortat: "Some people already visited him."
The NBA said it doesn't comment on security matters.