Military forces last week surrounded the home of Prime Minister Carlos Gomes in a coup just weeks before a runoff election. Gomes secured 49 percent of the vote last month, which wasn't enough for a clear victory.
The African Union said Tuesday that, in light of the "recurrence of illegal and unacceptable interference" in the country's politics, the country's membership was suspended "until the restoration of constitutional order," CNN quoted the union as saying in a statement.
The junta last week announced that it installed an interim administration made up of opposition leaders. The council is set to rule the country until later parliamentary and presidential elections.
A spokesman for the junta was quoted by CNN as saying Gomes and interim President Raimundo Pereira were in custody for "security reasons." Neither would return to power, the spokesman said.
None of the country's elected leaders has finished a term, succumbing to ailments, assassinations or military coups.
Last week's coup was condemned by the international community. The Economic Community of West African States said last week it had no tolerance for military claims to power.