Ethiopia had never recovered from the previous great famine of the early 1970s, which was the result of a drought that affected most of the countries of the African Sahel. The famine was also caused by an imbalance of population which was concentrated in the highland areas, which were free of malaria and trypanosomiasis. Both the Emperor's and Mengistu's regimes had tried to resettle people in the lowlands, but the Mengistu regime came in for heavy international criticism on the grounds that the resettlements were forced.