Another noose has been found in a museum along the National Mall in Washington.

A noose was seen hanging on a lamppost on Saturday afternoon outside the National Gallery of Art, U.S. Park Police spokesman Anna Rose confirmed to the Washington Examiner. It was found near the intersection of 3rd Street and Pennsylvania Avenue Northwest, she said.

Rose said the U.S. Park Police is investigating the case.

Two nooses were found near other museums on the Mall last month. On May 26, a noose was found in a tree by the Hirshhorn Museum. On May 31, one was found inside the National Museum of African American History and Culture.