A search is underway for two inmates who are missing from a state penitentiary, officials in Mississippi said Saturday.

The Department of Corrections said in a Facebook posting that David May, 42, and Dillion Williams, 27, were discovered missing from the Mississippi State Penitentiary at Parchman during an emergency count about 1:45 a.m.

May is serving a life sentence for two aggravated assault convictions in Harrison County, and Williams is serving a 40-year sentence for residential burglary and aggravated assault in Marshall County.

Five inmates have died in prison violence since Sunday; three of those deaths have occurred at Parchman. The prison is a series of cell blocks scattered across thousands of acres of farmland in Mississippi’s Delta region. Inmates who escape their cells sometimes don’t make it off the property.

Mississippi’s outgoing prisons chief said Friday that four of the five killings of inmates since Sunday stem from gang violence, as guards struggle to maintain control of restive inmates.

“These are trying times for the Mississippi Department of Corrections,” Corrections Commissioner Pelicia Hall said in a statement Friday.

All state prisons statewide remained locked down Friday, confining inmates to cells and blocking visitors.