Seven inmates have died and 17 others required outside medical attention after hours of fighting inside a maximum security prison in South Carolina.
Prisons spokesman Jeff Taillon announced the deaths after state police helped secure Lee Correctional Institution in the early hours of this morning.
Mr Taillon said multiple fights broke out between inmates at 7.15pm on Sunday.
He said no officers were wounded.
Earlier, state police were called to attend an "ongoing situation" at the the prison.
South Carolina state police have been called to an "ongoing situation" at one of the state's most dangerous prisons.
The South Carolina Corrections Department said on Twitter that State Law Enforcement Division agents responded just before midnight on Sunday to the situation at Lee Correctional Institution.
@SCDCNews and SLED are responding to an ongoing situation at Lee Correctional Institution.— SC Dept. Corrections (@SCDCNews) April 16, 2018
Some local media outlets reported the local coroner had been called to the scene.
The maximum-security facility houses about 1,500 inmates in Bishopville, about 55 miles from Columbia, and is home to some of South Carolina's most violent, longest-serving offenders.
In recent years, there have been several large-scale insurrections, including one in which an inmate overpowered a guard and used his keys to free others from their cells.
Two officers were stabbed in a 2015 fight. One inmate killed another during a fight in February.