EVANSTON, Ill. (CBS) — Evanston police were investigating Monday night, after three Evanston schools were the targets of racist mail.

Kingsley Elementary, Joseph E. Hill Education Center, and Park School were all targeted in the last few weeks with the same letter – which contained the N-word.

In a letter to Kingsley parents, the principal said in part: “This language is racist, hateful, and offensive. We are and will continue to be committed to equity, respect, inclusion, and the creation of a school that will allow all students to feel safe and affirmed.”

Evanston police would only confirm they were investigating and the letters were received recently.