A monument in Baltimore to Christopher Columbus — believed to be the first one erected to the Italian explorer in America — was vandalized.

Baltimore Police said they were looking into the incident, but couldn’t say when the damage took place.

A video posted to YouTube on Monday by a user named “Popular Resistance” shows a man striking the base of the monument near Herring Run Park repeatedly with a sledgehammer. Another person holds a sign that reads: “Racism, tear it down.” Another sign is taped to the monument reading: “The future is racial and economic justice.”

Police are searching for information about the men in the video, as well as whoever filmed it.