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Mizzou Legacy Circle at the Mel Carnahan quad on the campus of University of Missouri - Columbia, Nov. 10, 2015. Getty Images / Michael B. Thomas

Tensions continued at the University of Missouri on Thursday after police said they were investigating a report of vandalism at the Columbia campus' black culture center, the Associated Press reported. Police said someone spray-painted over a part of a sign at the center.

The word "black" on a sign at the Gaines/Oldham Black Culture Center was apparently spray-painted over, the Los Angeles Times reported. The sign was reportedly painted at about 12:50 a.m. and police said they were reviewing surveillance footage of the area.

The suspected vandalism comes just hours after black student protesters held an event to demonstrate against racist threats at Mizzou. The university's Black Student Government responded to the incident on Twitter, writing, "We're not afraid. You clearly are," along with what appeared to be a picture of the sign.

Police previously said that a threatening phone call had been made Tuesday to the center, according to the LA Times. The building was not evacuated. The Black Culture Center was also involved in previous racial turmoil in 2010, after two white students placed cotton balls on the lawn outside the building, which was received as a racist message by many students. The two students were later convicted of littering.

Two students at Mizzou were arrested Wednesday for making online threats, at least one of which was racially charged, amid student-led protests against alleged racism at the school. The threats, posted to social media app Yik Yak, said “I'm going to stand my ground tomorrow and shoot every black person I see" and "Well tomorrow mizzou will really make national news. Don't go to campus tomorrow," police reported, via ABC News.

Former University of Missouri President Tim Wolfe announced he would resign Monday after high-profile protests against alleged racism at Mizzou. The demonstrations included the college's football team threatening the cancelation of a game and a hunger-strike by a graduate student.