Mbuji-Mayi (əmbōˈjē-mĪˈyē) [key], formerly Bakwanga bäkwängˈgä, city (1984 pop. 486,235), capital of Kasai-Oriental province, S central Congo (Kinshasa), on the Sankuru River. A commercial center in Luba country, it handles most of the industrial diamonds produced in the Congo. After the Congo attained independence (1960) the city's population grew rapidly with the immigration of Luba people from other parts of the country. From 1960 to 1962 it was the capital of the secessionist Mining State of South Kasai.