WASHINGTON (AP) -- U.S. Park Police are trying to find a cruiser that was apparently stolen when it was supposed to be undergoing repairs in Brentwood, Md.

Police discovered the car was stolen early Saturday after a strange voice that seemed to impersonate an officer transmitted a message on the department's radio system.

Park Police spokesman Sgt. Robert Lachance says they could tell the voice wasn't an officer from the agency. He didn't give any details on what was said.

The stolen vehicle is a 1998 Ford Crown Victoria. It was part of the agency's canine unit and has a dog cage instead of a backseat.

The cruiser has police lights and is marked with the U.S. Park Police seal.

Officials say any residents who are pulled over by a Park Police cruiser should ask any plainclothes officer to show a badge.