STATE COLLEGE, Pa. - The governing council of Chi Omega has placed its chapter at Penn State University on probation after a photo circulated on social media of members wearing sombreros and fake mustaches depicting ethnic stereotypes.

The sorority apologized Wednesday after the photo, which included offensive signs, went viral.

One of the signs in the photo says "will mow lawn for weed + beer" and another reads "I don't cut grass I smoke it."

The two women holding the signs were among those wearing fake mustaches.

"I am disappointed in the choices made by our Nu Gamma Chapter members and we regret any pain caused," Chi Omega National President Letitia Fulkerson said in a statement released Thursday. "We are taking this situation very seriously. Chi Omega does not condone behavior that violates our organization's policy on human dignity."

Chapter president Jessica Riccardi told The Daily Collegian, the Penn State campus newspaper, that the sisters are sorry for "portraying inappropriate and untrue stereotypes."