Confederate flag poster with cotton attached found at American University in Washington D.C., U.S., September 26, 2017 in this picture obtained from social media. Michael Barry via REUTERS

(Reuters) - At least 10 images of Confederate battle flags with cotton plants stuck to them were put up around American University in Washington on Tuesday in an apparent protest of the school’s new anti-racist research center.

Campus police circulated images and videos on Wednesday of a white man wearing a yellow fluorescent vest and an orange hard hat, saying he was suspected of defacing school property by pinning the flag posters to various noticeboards around campus.

The posters appeared the same evening as a talk about the school’s new Anti-Racist Research and Policy Center by its founding director, Ibram X. Kendi, said Fanta Aw, the school’s vice president of campus life.

“AU is committed to the vision of the Center and Dr. Kendi’s work and we will not be deterred by this cowardly attempt at intimidation,” Aw said in a statement.

Sylvia Burwell, the university’s president, said she was angered to learn of the posters after leaving Kendi’s talk. “When one of us is attacked, all of us are attacked,” she said in a statement.

The Confederate battle flag was an emblem of the pro-slavery Southern states during the 1861-1865 Civil War.

There have been widespread demonstrations and rallies across the United States in recent months over Confederate monuments and symbols, notably in Charlottesville, Virginia, where a woman was killed during clashes between white nationalists and counterprotesters.

Some Americans want the flags and statues to remain in public view as a reminder of the nation’s history. Others see them as a glorification of the oppression of black Americans.