Penn State sorority Chi Omega put on probation for offensive picture

Updated at 3:29 p.m. ET

The national organization of a Penn State sorority announced Thursday that it placed the chapter on probation after a photo of its members wearing sombreros and holding offensive signs circulated on the Internet.

One of the signs in the photo of Chi Omega sisters says "will mow lawn for weed + beer" and another reads "I don't cut grass I smoke it." The two women holding signs are 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 posted on the organization's website. "We are taking this situation very seriously. Chi Omega does not condone behavior that violates our organization's policy on human dignity."

The national organization had said it was working on "educational directives" for the chapter and does not condone "personal degradation."

The Penn State chapter's probation will take effect Monday, according to the statement. The Penn State Panhellenic Council is investigating.

Penn State president Rodney Erickson and 17 other administrators issued a statement Thursday afternoon expressing their "feelings of deep disappointment and dismay" toward the students, but also suggesting they wouldn't face punishment from the university administration.

"These disturbing behaviors involved expressive rights protected under various federal and state laws - rights which we strongly support, and which we honor by not vainly pursuing unlawful disciplinary action against the students involved," the statement read.

Earlier, chapter president Jessica Riccardi told campus newspaper The Daily Collegian the sisters are sorry for "portraying inappropriate and untrue stereotypes."

Students told CBS Altoona affiliate WTAJ-TV they were appalled by the picture.

"It's just really grossly inappropriate in a lot of ways," graduate student Grant Berry told WTAJ-TV.

"It could just be like a Halloween party dressing up, but then they went as far as the signs," senior Taylour Maietta told WTAJ-TV. "That, I don't know, that might be stepping over the line a little bit."