An Iowa neo-Nazi has been arrested for allegedly threatening to “slaughter” Jews in messages to a Jewish organization, prosecutors say.

Garrett Kelsey, 31, allegedly left phone and email messages with a New York-based Jewish organization, sometimes threatening violence if they did not remove a YouTube video he disliked. Kelsey’s social media was filled with neo-Nazi references, as well as racist, anti-Semitic, and anti-Muslim memes.

Kelsey’s alleged campaign against the Jewish organization began with a video about neo-Nazis. The Jewish organization had made a video about a Scandinavian fascist movement, likely the Nordic Resistance Movement, which has been involved in violent attacks for years.

Kelsey took offense at the video, prosecutors say. He practiced Asatru, a pagan faith that is not inherently hateful, but which has a documented following among white supremacists. On May 23, he allegedly used an email with an Asatru reference to threaten violence against the Jewish group if they did not “remove this video and offer an apology to the Asatru community.”

Asatru draws on some Scandinavian roots, but a video about Scandinavian neo-Nazis is not an attack on Asatru. Nevertheless, Kelsey allegedly made more graphic threats over the phone. He called the organization, spoke to an employee, then called back and left a threatening message with the employee’s name, according to a criminal complaint.

“My people have fucking slaughtered your fucking people and we will do it again,” he allegedly said. “And right now, you are giving us an incentive to do that.”

Kelsey also allegedly made threats against local anti-fascists.

“I think you better second guess opening your little queer club here in Iowa,” he allegedly wrote on an Iowa anti-fascist Facebook page in May, according to the complaint. “If I ever see any of you cock sucking commie fascist snowflakes, I’m gonna bash your skulls in without warning! White is might!! 1488!! Hail Odin! Hail Asatru!!” (“1488” is shorthand for a white supremacist slogan and “heil Hitler.”)

The anti-fascist group said he left other threats on their page. “The day is coming where these scumbags are finally going to be recognized by our government as the lousy terrorists they are!” read one post, which the group shared with The Daily Beast. “We will kill Antifa for fun! Antifa are just a bunch of degenerates!”

Calling anti-fascists “terrorists” and appealing on the government to criminalize anti-fascism is a popular meme on the far right. Earlier this month, Republican Senators Ted Cruz and Bill Cassidy introduced a bill aimed at designating anti-fascists a “domestic terrorist organization,” despite anti-fascism not constituting an official organization.

Though he accused anti-Nazis of being terrorists, Kelsey’s internet presence was heavy with content that glorified violence. At the time of the criminal complaint, Kelsey’s Facebook header image was a picture of Jews being transferred to a Nazi concentration camp. His profile picture was a meme of a cartoon frog in a clown costume called Honkler (a play on “Hitler”).

Kelsey also maintained presences on extremist-friendly social media sites Gab, Minds, and Bitchute. His profile picture on Gab and Minds was a Sonnenrad, a symbol popular with neo-Nazis. On Minds he encouraged people to join openly Nazi communities, and made repeated attacks on immigrants, Jews, and Muslims.

He has been charged in New York with one count of interstate transmission of a threat to injure.