A middle-aged man stole an undisclosed amount of cash from an Annapolis bank yesterday and then fled by car after threatening to explode what he said was a bomb, the police said.

Police evacuated Annapolis Bank and Trust in the 1300 block of Cape St. Claire Road until they determined that the device was fake. Police were searching last night for the robber.

The man entered the bank at noon, placed what he said was a bomb on the counter and said he would detonate it if tellers sounded an alarm or put a dye pack in with the cash.

The man wore an earpiece connected by a wire to what appeared to be a radio on his belt, the police said. His sunglasses had a red light that flashed in the center of the frame.

He fled in what police said was a dark-colored compact car, driving south on Cape St. Claire Road toward U.S. 50.

Anne Arundel County police have turned over the investigation to the FBI, which a police spokesman said typically handles bank robberies.