Officer Dino Delimitros says the boy and a friend were throwing rocks in the Linda Vista neighborhood Monday afternoon when a passenger in a black Toyota RAV4 pulled out a crossbow and fired.
The boy was shot in the abdomen and was taken to a hospital. The San Diego Union-Tribune says his injuries are not life-threatening.
His name and age weren't released.
Nobody has been arrested.
Information from: The San Diego Union-Tribune