The detention of interim president Bah N’Daw and Prime Minister Moctar Ouane followed a controversial cabinet reshuffle that removed two members of the junta that overthrew Mali’s government in August.

The international body monitoring Mali’s 18-month transition to a civilian-led government — comprising the AU, the West African bloc known as ECOWAS, the United Nations and U.S. officials, among others — said in a statement that it “expresses its deep concern” over the arrests.