Reports say more than 100 prison inmates at the Kinross Correctional Facility in Kincheloe left their cells Monday and marched single file into the prison yard to demonstrate against their food menu.

Prison officials had received advanced warning so they were able to plan for the demonstration, which was peaceful, according to the Detroit Free Press.

The newspaper says menu options were among the complaints by the inmates. The demonstration comes two months after the state corrections department privatized its food service and eliminated 370 state jobs.

State corrections officials are investigating, and they say its likely the ringleaders will be disciplined, according to the Free Press.