SIOUX FALLS S.D. (KELO) — The Division of Criminal Investigation (DCI) is investigating reports of multiple assaults involving inmates Tuesday at the South Dakota State Penitentiary in Sioux Falls.

An estimated 10 inmates were injured and no staff were injured, a news release from the Attorney General’s Office said.

The assaults happened at the same time in different sections of the Jameson Annex. They were reported at about 1 p.m.

Evidence suggests the assaults were gang related, Attorney General Marty Jackley said in the news release.

Five inmates received stab wounds. Three were transported to Sioux Falls hospitals, and the other two were treated inside the prison. Additional inmates were injured from assaults involving homemade blunt objects, and others with fists and feet. 

DCI is working with the South Dakota Department of Corrections Office of the Inspector General on the investigation. All reports will be reviewed by the Attorney General’s Office for potential criminal prosecution, the news release said.