Seven inmates were killed and at least 17 more were injured after violence and chaos swept through at a maximum security prison in South Carolina, authorities said Monday.

Clashes among inmates at Lee Correctional Institution in Bishopville erupted at about 7:15 p.m. on Sunday, the state Corrections Department said. The fighting spread to three housing units, but no officers were wounded, authorities said.

Order was completely restored at about 3 a.m. Monday, the department said in a statement on its Facebook page.

"All SCDC staff and responding law enforcement officers are safe and accounted for," the statement said.

The department's police service unit and the South Carolina Law Enforcement Division were investigating.

The prison, which opened 25 years ago and holds about 1,700 of some of South Carolina’s most violent offenders, is itself no stranger to violence. Three weeks ago inmates overpowered a guard and holding him hostage and taking control of part of a dorm for about 90 minutes. The guard was released uninjured.

In February, one inmate fatally stabbed another in February.

On Monday, Lee County Fire and Rescue said it assisted with the "mass casualty incident" at the prison. Florence County EMS, Kershaw County EMS, Darlington County EMS, Lexington County EMS and Hartsville Rescue and a private ambulance service also responded.

The prison is about 50 miles east of Columbia. The state capital is home to the Kirkland Correctional Institution, where four inmates were fatally strangled a year ago. One of the two inmates accused of the crime said he killed them so he would be moved to death row.

Contributing: WLTX-TV in Columbia, S.C.