Under Soviet rule, all religious beliefs were suppressed by the communist authorities as superstition and "vestiges of the past". Most religious education and religious observances were banned. The vast majority of mosques were closed. An official Muslim Board of Central Asia based in Tashkent was established during World War II to supervise the Islamic faith in Central Asia. For the most of its existion, the Muslim Board functioned mostly as an instrument of propaganda. Atheism affected religious development and contributed to the isolation of the Turkmen people from the international Muslim community. Some religious customs, such as Muslim burial and male circumcision, continued to be practiced throughout the Soviet period, but most religious belief, knowledge, and customs were preserved only in rural areas in "folk form" as a kind of unofficial Islam unsanctioned by the state-run Spiritual Directorate.