Disturbing videos emerged Saturday that appear to show Kentucky high school students mocking participants of the Indigenous Peoples March in Washington D.C. on Friday—including a widely respected Native American elder from Omaha who served in Vietnam.

The videos, which have since gone viral on social media, show Covington Catholic High School students surrounding a group of marchers. The students from the all-boys school in the city of Park Hills, can be seen shouting and jumping as marchers start playing music.

The students were in Washington D.C. for the March for Life, an annual anti-abortion rally that coincidentally was taking place on the same day as the Indigenous Peoples March.

In a statement, the Diocese of Covington and Covington Catholic High School said “we condemn the actions of the Covington Catholic High School students towards Nathan Phillips specifically, and Native Americans in general.”

The school said it will investigate the matter and “take appropriate action, up to and including expulsion.“

“We extend our deepest apologies to Mr. Phillips. This behavior is opposed to the Church’s teachings on the dignity and respect of the human person," the statement said. “We know this incident also has tainted the entire witness of the March for Life and express our most sincere apologies to all those who attended the March and all those who support the pro-life movement.

Several students captured on video wear “Make America Great Again” gear, and several others are clearly wearing Covington apparel. One boy, who sports a “Make America Great Again” hat, appears to stand just inches from the face of Omaha Elder Nathan Phillips, who is singing and playing a drum. Phillips smiles calmly at the teen and continues to play.

“When I was there singing, I heard them saying, ‘build that wall! build that wall!’” Phillips said in a video posted to Twitter. “This is indigenous land—not supposed to have walls here. We never [did] for millennium.”

“Before anybody else came here, you never had walls, you never had a prison,” he also said. “We always too care of our elders. We took care of our children.”

Phillips, a Vietnam veteran and previous director of the Native Youth Alliance, is a “keeper of a sacred pipe” who leads an annual ceremony honoring Native American veterans in Arlington National Cemetery, according to Indian Country Today.

Phillips said he wished the young men’s energy was used “to making this country really great.”

New Mexico Democrat Deb Haaland, one of the first Native American women to serve in Congress, slammed the students on Twitter.

“This Veteran put his life on the line for our country,” she said. “The students’ display of blatant hate, disrespect, and intolerance is a signal of how common decency has decayed under this administration. Heartbreaking.”

Kentucky Secretary of State Alison Lundergan Grimes condemned the students’ behavior in a Facebook post, but largely placed the blame on the adults who shape their lives.

“In spite of these horrific scenes, I refuse to shame these children. Instead I turn to the adults that are teaching them and those that are silently letting others promote this behavior. This is not the Kentucky I know and love. We can do better and it starts with better leadership,” Grimes wrote.