OKLAHOMA CITY — A man helping out at a self-proclaimed “Muslim Free” gun store in the rural town of Oktaha, Oklahoma, accidentally shot himself in the arm after dropping his gun, authorities said on Wednesday.

The man involved in the Tuesday incident has not been identified and his injuries are not life-threatening, Muskogee County Sheriff Charles Pearson said.

The Save Yourself Survival and Tactical Gear store in Oktaha, about 120 miles (193 km) east of Oklahoma City, has a sign on a store window that reads: “This privately owned business is a Muslim Free establishment.”

The Council on American-Islamic Relations, an Islamic civil rights group, has filed a complaint with the U.S. Department of Justice asking for a federal investigation.

Armed citizens standing guard at the store have said the business had received death threats from around the world.

Save Yourself Survival and Tactical Gear said in a posting on its Facebook page the man who shot himself had a broken holster.

“He came over today to help fix a door in my office and as he bent over his weapon fell from a malfunctioning chest holster and went off when it hit the floor,” a store manager said.