An employee at the U.S. Mint in Philadelphia was placed on administrative leave after placing a noose on the chair of a Black colleague.

Surveillance video captured the white male coin maker walking across the factory floor with a noose in hand. The employee created the noose with rope used to seal coin bags at the U.S. Mint. Scores of Black workers contacted the union president the following day and the U.S. Treasury Department’s inspector general began an internal investigation.

U.S. Mint officials released the following statement:

“We have absolutely zero tolerance for the kind of misconduct reported at the Mint. Secretary Mnuchin has directed that this matter be handled swiftly and seriously. The investigation is moving ahead quickly. We strive every day for a workplace environment that is welcoming and safe for all.”

However, the national union has not released a statement on the matter.

Across the D.C. and Maryland region, nooses — considered a hate symbol by the the Anti-Defamation League — have been popping up in recent months. In May, a noose was discovered at the National Museum of African American History and Culture. Earlier this spring, bananas strung up by nooses peppered the campus of American University, also in the nation’s capital. The hanging fruits had been emblazoned with the letters of the Black sorority, Alpha Kappa Alpha, Inc.

In recent months, nooses have also popped up at the University of Maryland and outside of a middle school in Crofton, MD.