Students at Forest Grove High School in Oregon protested Thursday over a banner hung briefly in the school hallway this week that read “build a wall,” per a report by Oregon Live.

Chief of staff for the Forest Grove School District Connie Potter said the sign, which was put up on Wednesday, was up briefly, but prompted a rather quick response by the reportedly about half Latino student body.

Potter said the sign was put up after the school’s Unity Week. According to her, students had put up “unity-type signs,” and then a “build the wall” sign was hung over one of the posters.

She added that a teacher was able to remove the sign swiftly.

“It was immediately taken down, within literally a minute or two, and the students who hung it have been disciplined,” she said.

Students offended by the banner organized a demonstration and have taken to Twitter and Instagram to express their anger using the hashtag, #standupFG.

Hundreds of students from reportedly at least five other high schools walked out of class and marched on Main Street near Forest Grove.

“Build a wall” references presumptive GOP presidential nominee Donald Trump’s intentions to build a wall at the United States-Mexico border.