South African authorities say two inmates and two prison guards have been killed in an apparent hostage situation at a maximum security prison in Pretoria.
Officials said they were working to restore order at the facility Sunday and had begun an investigation into the incident.
Initial reports say the violence started after a firearm was smuggled into the prison.
Witnesses say two people were arrested in the prison's parking area amid the confusion. It was unclear if the arrests were related to the violence.
Some of this information provided by Reuters.