WASHINGTON - Seven inmates were killed and at least 17 others sustained serious injuries in a prison riot in the southeastern US state of South Carolina, authorities said Monday.

Clashes among inmates at Lee Correctional Institution in Bishopville took place at about 7:15 pm local time (2315 GMT) on Sunday and order was completely restored at about 3 am Monday (0700 GMT Monday), the state's Corrections Department said in a statement on its Facebook page.

No prison officers were wounded, it added.