Do you mean the Belgians in the last sentence?

Nazi racial theories grew out of intellectual currents that were widespread in early 20th century Europe, including theories of scientific racism and its close cousin, eugenics. These theories also helped to justify colonial rule broadly, including Belgian rule in the Congo.

Belgian racial theory is more commonly discussed in the context of Rwanda, where the Belgian administration ascribed racial difference to Tutsi/Hutu identity, and used a theory of Tutsi racial superiority to justify preferential treatment for the Tutsi population. The Tutsi were believed to have originated outside of central Africa; in mainstream colonial Belgian theories of race, Hutu and other central Africans were near the bottom of the racial hierarchy (although still above the Twa and other pygmy groups). This racial hierarchy also shaped colonial policy in the Congo, and indeed justified widespread violence. (I'm summarizing a large literature here; if you want to read further, you could start with Prunier's The Rwanda Crisis).

However, there were also important differences. Belgian rule in the early 20th century Congo was largely through concession companies, and the atrocities in the area were a result of efforts to get local populations to maximize rubber production. There was no grand ideological schema, in the manner of the Nazi party. Racial theory certainly made the atrocities possible, insofar as it made this kind of treatment of Africans thinkable, but it wasn't part of a genocidal project - unlike, for example, the German genocide of the Herero in Namibia or the Dutch genocide of the San in South Africa. If anything, Belgian officials in the Congo were worried that the African population of the region would die out and thus deprive them of a labor force (on Belgian population concerns, see Nancy Rose Hunt, A Colonial Lexicon, although be forewarned that the prose is kind of impenetrable).