On Tuesday afternoon mutinying soldiers made their way through the capital Bamako
The chair of the African Union, Cyril Ramaphosa, has demanded the release of Mali's President Ibrahim Boubacar Keïta.
"President Ramaphosa demands that the Malian military release from detention the President, the Prime Minister, Ministers and other government executives.
"President Ramaphosa calls for an immediate return to civilian rule and for the military to return to their barracks," said a statement from South African President Ramaphosa's office.
The European Union has already called for Mr Keïta's release, reports AFP news agency.
On Tuesday afternoon mutinying soldiers stormed Mr Keïta's residence and arrested the president and his prime minister - who were both there.
The president's son, the speaker of the National Assembly, the foreign and finance ministers were reported to be among the other officials detained.
On Tuesday night, Mr Keïta resigned in a brief address on state television.