A gun range owner who banned Muslims from her business as a matter of 'public safety' claims trade has 'quadrupled' since the controversial move.

Jan Morgan decided to bar all followers of Islam from her Gun Cave Indoor Firing Range in Hot Springs, Arkansas, last September while claiming the religion 'commands them to kill' her.

Five months on and she says business is booming and that threats of a lawsuit by federal civil rights enforcers have failed to materialise.

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Arkansas business owner Jan Morgan says business has boomed since she turned her shooting range into a 'Muslim-free zone'

The American-Islamic Relations had written to the Attorney General Eric Holder to investigate the gun range on the grounds of racial and religious discrimination.

The group's attorney, Jenifer Wicks, said at the time the move could 'inevitably result in a hostile environment for ordinary Muslims in Arkansas.'

But Morgan has no plans to back down, despite receiving threats over the contentious decision, and even claims business has 'quadrupled' with people coming from out of state and some offering donations for what they predict will be a legal battle.

Morgan claims keeping Muslims out of her firing range is a matter of public safety and not a constitutional issue

In a bizarre blog post, she wrote that she doesn't consider Islam to be a religion — and as such Muslims shouldn't be allowed protections under the U.S. Constitution.

'Why would I want to rent or sell a gun and hand ammunition to someone who aligns himself with a religion that commands him to kill me?' she added.

The shooting range owner said she made the decision in September after two customers she deemed suspicious visited. She said their furtive behavior and cellphone ringtones of 'Allahu Akhbar' prompted her to revise her range's policies.

Morgan, who says she has been threatened before, wrote in a rambling blog post: 'Why would I want to rent or sell a gun and hand ammunition to someone who aligns himself with a religion that commands him to kill me?'

Morgan said she excludes those she believes to be Muslim based on their names.

'We are dealing in lethal firearms,' Morgan told FoxNews.com. 'I'm not going to let a Nazi shoot in here, or a Ku Klux Klan member in here, either.'

She added in her blog that she believed the Koran contains '109 verses commanding hate, murder and terror,' and claims threats on her life have been made by Muslims.

Earlier this month, a Hindu father and son say they were turned away from the gun range.

The men, of Indian descent, said they had arrived hoping to shoot but were immediately asked where they were from and told it was a Muslim-free range.

Despite telling Morgan they were Hindu, the son, who did not want to be named, claims he and his father were still asked to leave.

The American Civil Liberties Union (ACLU) of Arkansas has now petitioned federal authorities against Morgan's decision.

Executive Director Rita Sklar said the rule was religious discrimination and warned her group would be 'more than happy' to proceed with legal action should a client approach them.

Morgan is the owner of the Gun Cave Indoor Shooting Range (pictured) in Hot Springs, Arkansas

Legal experts say Morgan may be within her rights if her gun range is deemed a private club. However, they warned that a gun range open to the general public but excluding Muslims could struggle to prove it does not fall under federal civil rights regulation.

Morgan cited the terrorist attacks of September 11, 2001, and the Boston Marathon bombings as some of the reasons she mistrust Muslims.

Morgan said some of her patrons were 'frightened' when two men with 'Allah Akbar ring tone and message alert tones' — the Arabic phrase meaning 'God is the greatest' — walked into her range recently.

'They spoke very little English, one did not have proof of U.S. citizenship, yet they wanted to rent and shoot,' Morgan wrote. 'They were constantly glancing toward the cameras in the range, then looking at each other and speaking in their own language.

'Their behavior was so strange, it frightened my patrons. No one would enter the range to shoot while they were there. Some of my customers left. I lost business and the people who remained at my facility said they did so out of fear for my safety.'

Morgan was unavailable for comment when sought by MailOnline on Thursday evening.

The Council on American-Islamic Relations has asked the U.S. Department of Justice to investigate Morgan (pictured) on ground of racial and religious discrimination

In a phone call, an employee at Gun Cave Indoor Shooting Range said Morgan is considering changing her business into a private shooting club.

'As such, we can say who may or may not be a member,' the staffer said. 'We don't ask anybody what their religion is, we don't care.

'They come in here and act normal, we don't have a problem.'

Bizarrely, Morgan seems to justify her Muslim-free idea on the advice of agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

She claims two agents told her 'if we feel ANY reason for concern about selling someone a firearm, even sense that something is not right about an individual, or if we are concerned about that [person's] mental state, even if they pass a background check, we do not have to sell that person a gun.

She added: 'I understand that not all Muslims are terrorists. I also believe there are as many Muslims who do not know what is in their Koran as there are Christians who do not know what is in their Bible.

'Since I have no way of discerning which Muslims will or will not kill in the name of their religion and the commands in their Koran, I choose to err on the side of caution for the safety of my patrons.'

The Council on American-Islamic Relations sent a copy of its letter to Arkansas Gov. Mike Beebe, the Civil Rights Division of the U.S. Justice Department, the U.S. Attorney for the Western District of Arkansas and the ATF's regional office in Little Rock.