COLORADO SPRINGS, Colo. (AP) — Colorado corrections officials say a prison inmate has died after being assaulted by other inmates.

Department of Corrections spokesman Mark Fairbairn says in a statement that Daniel Pena was assaulted on Nov. 20 at the Cheyenne Mountain Re-Entry Center, a private prison in Colorado Springs. Fairbairn says Pena died on Sunday.

Details of his injuries haven't been released.

Online prison records say Pena was 64 years old. He received a four-year sentence in August of 2014 after pleading guilty to assault in Denver County.

Fairbairn says the offices of the department's Inspector General and El Paso County District Attorney are investigating Pena's death as a homicide.