LINCOLN, Neb. (AP) — Officials say chemical agents were used to quell a disturbance by six inmates at the Nebraska State Penitentiary in Lincoln.

Nebraska Correctional Services Department spokeswoman Dawn-Renee Smith said Tuesday’s disturbance lasted more than three hours. No injuries have been reported, but one staffer sought medical care for smoke exposure.

Smith says the incident began when inmates slid burning items out of their cells. The fires were quickly extinguished, but Smith says the housing unit gallery filled with smoke and had to be evacuated.

She says a chemical spray was used on one inmate who tried to strike a staffer, and two chemical munitions were fired from a tower to control other noncompliant inmates.