A woman who went to visit a friend at D.C. General Hospital was accosted by a man in a hallway, taken through an elaborate series of tunnels in the basement to a secluded area of the hospital and raped, D.C. police and hospital authorities reported.

Police said the 25-year-old woman, from Northeast Washington, was assaulted about 5:30 p.m. Friday while on her way to visit a sick friend.

She was treated at the hospital for injuries suffered in the attack and released, according to a hospital spokeswoman.

Police said the incident occurred as the woman was getting off an elevator on the third floor of the hospital, located at 19th Street and Massachusetts Avenue SE.

They said she was approached from behind by a man who forced her into a stairwell and beat her about the face and head. Hospital spokeswoman Penelope Anderson said the woman was then "manuevered" through a series of tunnels to a secluded area in the basement, where she was raped.

"Obviously the man knew the hospital complex very well and moved her to an isolated area knowing that people were off duty around 5 o'clock," Anderson said.

She said Friday's rape was the first violent crime to occur on the hospital grounds in more than two years. She said the hospital, which "beefed up" its security staff last year, will review its security procedures to determine whether there was any lapse.

"It's one of those incidents that can happen at any institution," she said. "There are an incredible number of ways to get into this complex. We try to screen and admit people coming in and out of here at all times of the day and night."

However, she said, "There are five or six entrance doors in our core building alone" and the hospital staff cannot monitor the movements of every visitor and patient.

Friday's rape was the third violent incident at a Washington hospital in eight months. On Oct. 14, 84-year-old Selena Toye was stabbed to death in her bed at the Washington Hospital Center in what D.C. police said was an apparent "mercy killing." And in early April, a 62-year-old patient at Howard University Hospital was sexually assaulted in her room.