One of the St. Louis region’s most prestigious college preparatory schools said it plans to discipline a group of students who exchanged a private series of racist, profane and sexual Snapchat messages that were leaked to a wide online audience.

The Mary Institute and St. Louis Country Day School, a private pre-K to 12th-grade school in the affluent St. Louis County suburb of Ladue, began investigating the Snapchats after a student posted screenshots of the messages on Twitter on Sunday. The Twitter post was shared by at least 280 people as of Monday afternoon.

In the messages, at least three different people used the N-word. Another user wrote, “Shoot guys does anyone know how to send in their applications for the KKK? Mine won’t sumbmit (sic).” The messages also include repeated racist sexual references that are too profane for the Post-Dispatch to include in this story.

The students continued using the N-word despite protests from at least two other people on the message thread.

In one screenshot of a later message exchange, a Snapchat user who wrote offensive language claimed to another user that “we were all joking.”