WICHITA, Kan. (AP) – Members of a Native American sweat lodge at a VA hospital in Wichita have been subjected to discrimination and “blatant hostility” aimed at shutting down their religious services, according to a letter sent by a religious liberties group Wednesday to the U.S. Department of Veterans Affairs.

Among the concerns outlined by the Liberty Institute was the recent suspension of a substance abuse counselor at the Robert J. Dole Veterans Affairs Medical Center who also was the spiritual leader of the center’s sweat lodge. The group alleges his suspension came in retaliation for his advocacy work for the sweat lodge after a new supervisor tried to shut it down, and that his absence has effectively ended the religious services.

Sweat lodges, which have been erected at more than a dozen VA hospitals nationwide, are huts used by Native Americans for religious ritual steam baths for purification.

“If anybody’s religious liberty rights should be vindicated it should be those of the veterans who fought for everyone else,” Hiram Sasser, an attorney for the Liberty Institute, told The Associated Press in an interview Wednesday.

The Liberty Institute, which is representing the sweat lodge members, asks the VA to respond by July 6 about steps it will take to ensure the continued operation of the sweat lodge. Such letters are oftentimes precursors to lawsuits.

The medical center released a statement that didn’t address the specific allegations, but said the center has prioritized supporting the religious practices of its staff, volunteers and veterans. It also said its staff has “worked tenaciously” to ensure the sweat lodge program was a success, including meeting with a Lakota Nation medicine man.

“Through our dedicated chaplain corps we have afforded multiple avenues for the free practice of religious and spiritual practices throughout the medical center – such as the Native American practice of the Sweat Lodge,” the center said.

In its letter, the Liberty Institute alleges that a supervisor hired in March told the sweat lodge’s leader that he could no longer hold dinners at the center following the monthly ceremonies. The supervisor also said supplies such as towels and disposable plates couldn’t be stored in his VA office, and ordered him to remove Native American religious items such as prayer flags and a religious staff.

In May, the VA met with a Lakota medicine man from South Dakota who oversaw the center’s sweat lodge leader, and assured them that the agency fully supported the sweat lodge and would allow the meals and supplies storage to continue. But in June, the supervisor suspended the sweat lodge leader from his VA job as a substance-abuse counselor and told him he couldn’t contact members, according to the letter.

The counselor didn’t return a phone message from the AP seeking comment Wednesday. Sasser, the Liberty Institute attorney, said the group did not represent the counselor in regards to the letter.