Four Annapolis residents returning home yesterday after a day of sightseeing in Washington were robbed at gunpoint aboard a New Carrollton-bound Metro train, Metro authorities reported.

Police and Metro spokesmen said the four robbers, one of whom struck a woman holdup victim in the face with a pistol, escaped with about $800 worth of cash and camera equipment after the late afternoon incident, which occurred between Cheverly and Landover on the Orange Line.

One of the victims, Nancy Childes, 32, an Annapolis area hairdresser, said the holdup occurred shortly before 6 p.m., just after four youths in their late teens entered the car at the Cheverly station. Two of the youths stood in front of Childes and her husband, Robert, 28, while the other two took seats behind her friends, Kathy Williams, 21, and Donny Rohrback, 23, Childes said.

Seconds later, Childes said, she and her husband were staring down the barrel of a pistol, and one of the youths behind Williams and Rohrback was pointing another handgun at their faces.

"They just pulled the guns and said, 'Hand over everything you've got.' It was so quick." Childes said one of the gunmen struck Williams across the face with his pistol when the victims seemed reluctant to give up their valuables. She was not seriously injured. There were about a half dozen other people in the car, but they were not approached by the robbers, Childes said.

The robbers left the train at the Landover station, and the four victims got off a stop later at New Carrollton, the last stop on the line, and reported the incident to Metro attendants. The robbers were still being sought last night.