What does the cryptic crossword clue "African people incarcerated when borders removed (4)" mean?

The definition is "African". The wordplay uses a deletion. HUT (deletion) + U (deletion) = HUTU; definition: "African" The answer is HUTU.

African people incarcerated when borders removed (4)

Guardian Cryptic #29389 | 21 Across | 2024-05-22 flower