Yes, "interment camp" is a euphemism for "concentration camp", but to be fair at about the same time "concentration camp" become a euphemism for "death camp".
And "concentration camp" is itself a euphemism for "prison camp". So its probably better if we strip out the euphemisms and refer to:
1. "Prison camps", and
2. "Death camps" (or, even more accurately, "Extermination camps")
(Recognizing that the second is a subset of the first, not a disjoint category.)
And avoid "concentration camps" and "internment camps" entirely.