CHICAGO (WLS) -- Thousands of nurses who went on strike at the University of Chicago Medical Center were turned away from hospitals as they attempted to return to work on Saturday.
On Friday, 2,200 University of Chicago nurses traded in their scrubs for picket signs.
Although the nurses have agreed to a 24-hour strike, which means they'd return to work Saturday morning at 7 a.m., hospital officials said replacement nurses needed a five-day guarantee to work through Tuesday. Hospital officials said union nurses will be allowed to return to work on Wednesday, September 25.
RELATED: University of Chicago Medical Center moves patients to other hospitals in anticipation for nurses' strike
University of Chicago Medical Center's contract with the National Nurses Union expired in April. Nurses are demanding better staffing at the hospital. They said shortages are putting patients at risk.
Hospital officials said the hospital has been negotiating with nurses since March, and that the nurse staffing levels are the best in the state.
Nurses not allowed to return to University of Chicago Medical Center after strike