The Ovimbundu (singular Ocimbundu, adjective and language Umbundu), also known as the Southern Mbundu, are a Bantu ethnic group who lives on the Bié Plateau of central Angola and in the coastal strip west of these highlands. As the largest ethnic group in Angola, they make up almost 40 percent of the country's population. Overwhelmingly the Ovimbundu follow Christianity, mainly the Igreja Evangélica Congregacional de Angola (IECA), founded by American missionaries, and the Catholic Church. However, some still retain beliefs and practices from African traditional religions.