Making a U-turn at 15th and H. Policeman hold up hand, I stop car, he walks toward curb, apparently talking to someone. My car is moving directly toward several women pedestrians who are walking from right to left. Policeman motions me ahead, and I complete turn into Bladensburg Road, along east side of which something like a carnival is in progress -- many small, open booths and crowds of people milling about. Start out along Bladensburg Road conscious of being followed by 3 boys (12 to 14 years old) at least one of them on a bicycle. Soon I realize the boys are on or in the car and I therefore stop, and find them both on rear of car, outside, and also in the rear seat section. There is a considerable variety of articles on rear seat. Put boys off of car.