Charges have been filed against five inmates in connection with a May riot at the state prison in Tecumseh that left two inmates dead, authorities said Thursday.

The Nebraska attorney general's office said in a news release that the five inmates charged each face felony counts. William Harris is charged with making terroristic threats toward a correctional employee. John Zalme, Roger Weikle and Frederick Gooch each are charged with assault by a confined person on an officer. Ian Yelton is charged with first-degree assault.

They are the first charges stemming from the May 10 riot, state prisons spokeswoman Dawn-Renee Smith said.

Harris is serving 51 to 73 years for first-degree assault, a weapons conviction and fleeing to avoid arrest. Zalme and Weikle have lengthy sentences as habitual criminals for various violent crimes. Gooch is serving up to 30 years for drug dealing and assaulting an officer.

Yelton is serving up to 50 years in prison for sexual assault.

Smith said phone interviews with the inmates were not being allowed Thursday.

No one has yet been charged in the deaths of two sex offenders who were found dead at the prison once order was restored after the riot. Two guards and four inmates were injured.

An investigative report released in June concluded that the riot started after too many prisoners were allowed to leave their cells at once to get medication while the prison was at minimum staffing levels.

Officials said Thursday that the deaths and property crimes related to the riot are still under investigation and additional charges could come.

State prisons director Scott Frakes said Thursday that the charges against the five inmates sent "a strong message that assaultive behavior toward staff or other inmates will not be tolerated."