NEW YORK (AP) -- A noose was found dangling outside a ground zero post office that was damaged in the Sept. 11 terrorist attacks, police and a postal official said. They said it wasn't clear, however, whether the hated symbol of lynchings in the Old South was directed at the postal service or any other tenants in the lower Manhattan building. "At this point, there was no target that was evident or any motive,'' U.S. Postal Inspection Service spokesman Al Weissman said Friday morning. He said no postal workers had reported any threats or other problems. The U.S. Postal Service's Church Street station shares the building with the city Housing Authority, some state agencies and various other tenants. Dangling from a lammpost near the building, the noose was visible from the street, Weissman said. But postal workers were the first to notice it Thursday afternoon, he and police said. The building facade is undergoing work and laced with scaffolding that leads to the light pole, but the scaffolding is covered with barbed wire, Weissman said. Building managers removed the noose, which was later turned over to the NYPD's hate crimes unit for investigation, police said. The post office at 90 Church St. was closed for nearly three years after the 2001 terrorist attacks, which left the 15-story building contaminated with asbestos, mercury and debris from the fallen twin towers. The repairs to the post office entailed demolishing interior walls, replacing some elevator parts and restoring the 1935 building's art deco lobby. The discovery of the noose came as police tried to determine who left another noose this week on a Columbia University professor's door, a discovery that has shaken the Ivy League campus. Nooses have appeared in recent incidents around the country. Three white students hung nooses from a tree outside a high school last year in Jena, La., fueling racial tensions. Other nooses have been found recently at the U.S. Coast Guard Academy in New London, Conn., and the Hempstead Police Department's locker room on Long Island.