A 17-year-old Northwest Washington youth was killed and five persons, including a Prince George's County police officer, were injured yesterday when a stolen car being chased crashed into a parked police car in Langley Park, according to police.

Police said they began chasing the car on southbound New Hampshire Avenue in Langley Park about noon after seeing it speeding. When the officer learned that the car was listed as stolen and attempted to stop the car, its driver increased speed, police said.

While traveling at speeds of more than 80 mph, the driver apparently lost control of the car near Sligo Creek Parkway, swerved into the median strip, crashed head-on into a police car parked there and slammed into a utility post.

A front-seat passenger in the speeding car, Keith Francis Parker of 4431 New Hampshire Ave., died of his injuries. Details on the other passengers in the car were not available, but police said they were being treated for injuries at area hospitals.

The injured police officer, Keith Evans of the Hyattsville police station, was taken to Washington Adventist Hospital and was being treated for head and leg injuries, police said.

The driver of the car, whom police declined to identify because of his age, had not been charged in the incident last night.