PHILADELPHIA — A 20-year-old man jumped out of a car during a traffic stop Monday and shot a rookie officer in the face at close range with a single blast of a sawed-off shotgun, police said.

Officer Richard Decoatsworth, 21, was undergoing reconstructive surgery after being hit in the left side of his face with birdshot, police said.

"The officer was very, very lucky," Police Commissioner Sylvester Johnson said.

The assailant held the shotgun "a matter of inches" from Decoatsworth's face when he pulled the trigger, which may have stopped the shotgun pellets from spraying out fully and doing more damage, Johnson said.

Decoatsworth was shot at about 9 a.m. shortly after he pulled over the car being driven by the alleged shooter and containing three younger passengers, who were in school uniforms, Johnson said.

The car pulled over and the occupants got out and started walking away, prompting Decoatsworth to call them back to the vehicle, Johnson said. The suspect reached inside the car, pulled out the shotgun, jumped on the hood of the car and fired, he said.

Decoatsworth returned fire and gave chase on foot for three blocks but was forced to stop because he had lost a large quantity of blood.

Johnson said witnesses quickly called police when they saw the suspect unsuccessfully try to break into a nearby house in an apparent attempt to hide. Scores of officers flooded the West Philadelphia neighborhood and quickly found the suspect hiding in bushes in a nearby alley with the shotgun nearby.