They are also spoken in Cameroon, Chad, the Republic of Congo, and South Sudan.
[1] However, this has become increasingly uncertain, and Dimmendaal (2008) states that, based on the lack of convincing evidence for a Niger–Congo classification ever being produced, Ubangian "probably constitutes an independent language family that cannot or can no longer be shown to be related to Niger–Congo (or any other family).
[5] The half dozen remaining branches are coherent, but their interrelationships are not straightforward.
Williamson & Blench (2000) propose the following arrangement: In addition, there is the Ngombe language, whose placement is uncertain due to a paucity of data.
Güldemann (2018) recognises seven coherent "genealogical units" within Ubangian, but is agnostic about their positions within Niger–Congo.