DES MOINES, Iowa (AP) — The Polk County Sheriff’s Office says insubordination and gender bias led to the firing of a sergeant who was being investigated for social media postings deriding Islam.

Sgt. Dan Charleston was fired Friday. The investigation was launched after a graphic on Charleston’s Facebook page included what it said were “verses from the Quran that inspire terrorists.” The post included a comment from Charleston that read: “No reasoning with this evil ideology.” The posting has since been removed.

The Sheriff’s Office said in a news release Monday that “the recent social media postings made by Charleston about the Quran and Muslims were not a factor in any way with his separation from the sheriff’s office.”

Charleston has said he will appeal his firing but declined to comment further.