Seven prison inmates were killed and 17 injured in an hours-long series of events involving multiple fights between inmates at a prison in South Carolina, the state Corrections Department said on Twitter.

The Lee Correctional Institution in Bishopville, South Carolina, about 40 miles (64 km) northeast of the state capital Columbia, was secured at 2:55 a.m. ET, hours after the incident which began around 7:15 p.m. ET (2315 GMT) on Sunday night, the department said. It said that the incident played out over three housing units.

All prison staff and law enforcement were safe and accounted for the, Corrections Department said on Twitter.

 Reporting by Rich McKay in Atlanta and Ian Simpson in Washington; Writing by Scott Malone; Editing by Chizu Nomiyama