Officially, North Korea is an atheist state. There are no known official statistics of religions in North Korea. According to Religious Intelligence in 2007, 64% of the population are irreligious, 16% practice Korean shamanism, 14% practice Chondoism, 4% are Buddhist, and 2% are Christian. Freedom of religion and the right to religious ceremonies are constitutionally guaranteed, but religions are restricted by the government. Amnesty International has expressed concerns about religious persecution in North Korea.