Warning: This story contains offensive images and language from social media posts.

OREGON CITY, Ore. -- Students at Oregon City High School walked out of classes Thursday morning to protest several incidents of racism involving OCHS students.

After leaving the buidling, school administrators steered them into an internal courtyard.

The first incident happened Monday and involved a tweet that shows a group of people holding a sign that includes a racial slur and a drawing of what looks like a Ku Klux Klan member.

The tweet caused backlash against the person who sent it and the people in the photo.

It also prompted two letters from the school and the district to OCHS parents. Principal Tom Lovell told parents in one letter that the photo upset a lot of students because OCHS students were in the picture.

Part of his letter reads:

"The language on the sign and the drawing in no way represent the students and staff of our school, the environment that we are trying to create here, or the community we live in. I know that many of you were also embarrassed because of this, and so was I.

I want to thank the students who first brought this to the attention of their teacher. Standing up for what’s right is often difficult to do. I know that many other students had the courage to talk with their teachers as well, and I thank you for doing that."

Other tweets said some of the people in the photo were graduates and that the group was welcoming home a friend from college.

The second incident involves high school basketball star N'Dea Flye. She tweeted out this photo Tuesday.

Flye has verbally committed to play basketball for the University of New Mexico and says she's been offered a full scholarship.

The walkout gathering made her feel supported.

“It’s so great that my community can support me and everybody of color… and that we could all come together and do this, it was really amazing,” said Flye.

Other students brought their message to news media gathered on a sidewalk at the edge of campus. Their main message was that the vast majority of the 2,300 students at the high school are not racist, and stand for better values.

One student said she was glad the message was getting out, despite the media being kept away.

“I think the reason why they changed it is because you guys were out here but I was really surprised they changed it… because I think it would have been better to have it out in front of the school,” said Brynn Sare.

Some leaders and members of Don’t Shoot Portland were allowed on campus to take part in the gathering.

The Oregon City High School website show a candlelight “unity gathering” is scheduled for Thursday night at 7:30 p.m., presumably at the school entrance.

A spokesperson for the district says the principal has addressed the incidents with students and started an immediate investigation.

"Leadership is proud of our students for immediately reporting these offensive incidents and for coming together to plan unity events on Thursday," said Michael Clark, communications specialist for Oregon City School District.