(CNN) An Iowa man has been arrested by federal agents after he threatened to kill Jews in hate-filled phone calls and emails, according to court documents.

Garrett Kelsey, 31, admitted in a voluntary interview to calling and emailing a Jewish organization with messages full of anti-Semitic and racist language, the documents said. He was arraigned on Tuesday in a federal court in Iowa on charges of making interstate threats.

Kelsey was apparently upset about a video regarding Nordic neo-Nazis that the group had posted, the affidavit said.

"My people have f***ing slaughtered your f***ing people before and we will do it again. And right now, you are giving us incentive to do that. ... Filthy f***ing Jews," Kelsey said in a message to a Jewish organization based in New York, according to court documents.

Kelsey's profanity-laced email to an employee warned the group had three days to remove the video or "we will be taking action against your organization full of degenerates," the affidavit said. The Cedar Rapids resident also wrote that "everywhere Jews go in the world they cause trouble."

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