Baltimore County police are investigating an incident of vandalism over the weekend at Dumbarton Middle School, where white-supremacist symbols were spray-painted on a wall and scrawled on the side of a van.

The graffiti was reported shortly before 9 a.m. Saturday by a resident of Dumbarton Road in the school's Rodgers Forge neighborhood.

Police arrived to find "White Power KKK" spray-painted on an exterior school wall and another inflammatory statement featuring a racial slur toward African-Americans painted on the side of a 2001 Ford van parked at the school.

School crews cleaned up the graffiti hours after its discovery, in time for today's scheduled opening of classes in county schools.

Police Sgt. William Watts of the Towson Precinct said the vandalism occurred overnight, and that leads were being investigated.

Charles A. Herndon, spokesman for the county schools, said the system also is investigating the incident but had no other comment.