The Dimitrovist Pioneer Organization "Septemberists" was a pioneer movement in Bulgaria founded in September 1944. The DPO "Septemberists" organized children between 9 and 14 years old. Its day-to-day affairs were supervised by the Dimitrov Communist Youth Union. A 1967 estimate put its membership at about 700,000. A similar organization called the chavdarcheta existed for younger children who would later become pioneers. The two could be differentiated by their members' distinctive scarves, which were sky-blue in the chavdarcheta movement and red in the pioneri movement.