Fifteen Illinois law enforcement officers were charged Tuesday in an F.B.I. sting on counts that included accepting cash in exchange for providing armed protection for drug dealing operations in south suburban Chicago.

Patrick J. Fitzgerald, United States attorney for the Northern District of Illinois, who described the charges as “particularly shocking,” said two of the officers helped an undercover Federal Bureau of Investigation agent unload and deliver duffel bags stuffed with drugs that had been flown in on a private plane.

“Ideally, it should be hard to find one corrupt officer,” Mr. Fitzgerald said in a written statement, “and it should never be easy to find 15 who allegedly used their guns and badges to protect people they believed were dealing drugs, instead of arresting them.”

The defendants were charged with conspiracy to possess and distribute cocaine and/or heroin in drug dealing operations that played out in parking lots at suburban shopping centers and hotels. They include 10 Cook County sheriff’s correctional officers, two of whom are on active duty with the National Guard in Afghanistan; four officers with the suburban Harvey Police Department; and one Chicago police officer. Two other men who were not affiliated with the law enforcement agencies were charged as well.