SUSANVILLE  (AP) — California corrections officials say a 28-year-old inmate died after he was attacked by three other inmates using homemade knives.

The inmate died shortly before 11 a.m. Thursday at High Desert State Prison in Susanville, near the Nevada border. His name was not released because relatives had not been notified.

He was serving a life sentence from Los Angeles County for robbery, assault with a deadly weapon and attempted murder.

The Department of Corrections and Rehabilitation says the three suspects all are serving life sentences from Los Angeles County. Two were convicted of murder and the third of carjacking while using a firearm.

Two inmate-made knives were found at the scene.

Other inmates’ activities are being limited while the assault is investigated. The prison holds more than 3,300 inmates.