Northern Nevada Correctional Center has been locked down since Saturday because of a fight.
Director of Corrections Glen Whorton said the fight involved four inmates late Saturday.
"It was just a fight. Nobody got hurt. We're talking some stitches," he said. "But the warden wants to know exactly what was going on."
NNCC is a medium security facility along the southern border of Carson City. As of Monday, it housed 1,289 male prisoners and seven women awaiting transfer to the women's prison in North Las Vegas.
Warden Don Helling ordered the institution locked down until his investigators can sort out exactly what caused the fight.
Whorton said if it's just two inmates, that may be just a fight. But when there are four or more involved, prison officials get worried about the root causes including potential gang activity.
"We want to make sure we don't have something more going on," he said.
Lockdown means there is no freedom of movement by inmates in the institution. They are escorted to meals, some programs are canceled and recreational activities are restricted.