Cook County Sheriff Tom Dart is Unavailable for Comment - He is still hiding under his desk
A fight broke out among detainees at around 1:30 p.m. and was quickly brought under control, a jail spokeswoman said. Several weapons were recovered, she said.
Those injured -- four charged with murder and one with armed robbery -- were transported in serious to critical condition to Mt. Sinai and Stroger hospitals, according to the Chicago Fire Department.
Injuries sustained in the fight included puncture wounds.
It wasn't immediately known what led to the incident or who it involved, and the source of the weapons is under investigation.