An inmate who stabbed four fellow prisoners and a guard in separate, bloody attacks that led to internal prison security changes is on a hunger strike inside Ohio's toughest lock-up, alleging mistreatment.

Inmate Greg Reinke said he's being harassed by guards, denied proper recreation time and lives in a bare cell so empty that he's forced to place his clothes on the floor. He said inmates who have been convicted of killing guards aren't being treated as poorly as he and fellow inmate Casey Pigge, also charged in the guard's attack.

"But for us it's like they've come up with their own set of rules and procedures," Reinke told The Associated Press in an April 7 letter. It "seems as if they make it up as they go along."

The two are housed in the state supermax in Youngstown, a facility typically reserved for inmates with bad prison behavior records.

Reinke had missed 14 meals as of Tuesday, meeting the agency's definition of a hunger strike, said Sara French, a spokeswoman with the Department of Rehabilitation and Correction. Pigge is not on a hunger strike, she said.

French denied Reinke is being mistreated, but acknowledged he's held at a high-security level because of his "assaultive behavior." That level does not allow meeting with other inmates for church services or group activities, she said.

A message seeking comment was left for Reinke's lawyer. Reinke alleged similar mistreatment in January, which was also denied by the prison system.

Reinke, 38, pleaded guilty last month to charges including attempted murder for the attacks at the Southern Ohio Correctional Facility in Lucasville.

Reinke was sentenced to 54 years for using a homemade knife to repeatedly stab handcuffed prisoners after slipping his own handcuffs in 2017. The bloody attack on prisoners caught on a video obtained by the AP.

Reinke was sentenced to an additional 32 years behind bars for an attack about eight months later on a corrections officer. Prosecutors allege Reinke and Pigge stabbed the officer 32 times.

Pigge has pleaded not guilty, and his case is pending. Pigge previously was convicted of three separate killings, including strangling a fellow inmate on a medical transport bus.

At the time of the attacks, Reinke was serving a life sentence for aggravated murder for a 2004 shooting in Cleveland.

Last month, two inmates attacked by Reinke in the June 2017 stabbing filed a federal civil rights lawsuit against the warden of the Southern Ohio Correctional Facility, two officers and other staff over the assault.