A diocese has apologised after videos emerged showing students from an all-male Catholic high school mocking Native Americans after a rally in Washington.

The Indigenous Peoples March on Friday coincided with the March for Life, which drew thousands of anti-abortion protesters, including a group from Covington Catholic High School in Park Hills, Kentucky.

Videos circulating online show one youth staring at and standing extremely close to Nathan Phillips, an elderly Native American man singing and playing a drum.

Other students, some wearing Covington clothing and many wearing red “Make America Great Again” hats and sweatshirts, surrounded them, laughing and jeering.

In a joint statement, the Roman Catholic Diocese of Covington and Covington Catholic High School apologised to Mr Phillips.

Officials said they are investigating and will take “appropriate action, up to and including expulsion”.

The statement said: “We extend our deepest apologies to Mr Phillips.

“This behaviour is opposed to the church’s teachings on the dignity and respect of the human person.”

According to the Indian Country Today website, Mr Phillips is an Omaha elder and Vietnam veteran who holds an annual ceremony honouring Native American veterans at Arlington National Cemetery.

In a video posted online, he wiped away tears as he said of the incident: “When I was there singing, I heard them saying ‘Build that wall, build that wall’.

“This is indigenous lands. We’re not supposed to have walls here. We never did.”

He said he wished the group of youngsters would instead put their energy into “making this country really great”.

State politician Ruth Buffalo, a member of the Mandan, Hidatsa and Arikara Nation, said she was saddened to see students showing disrespect to an elder who is also a US military veteran at what was supposed to be a celebration of all cultures.

“The behaviour shown in that video is just a snapshot of what indigenous people have faced and are continuing to face,” she said.

She added that she hopes it will lead to some kind of meeting with the students to provide education on issues facing Native Americans.

Congresswoman Deb Haaland, who had been at the rally earlier in the day, sharply criticised what she called a display of “blatant hate, disrespect, and intolerance”.

She tweeted: “This Veteran put his life on the line for our country. Heartbreaking.”