The interim president and prime minister of Mali resigned on Wednesday, two days after they were arrested by the military, an aide to the vice president said, deepening a political crisis and potentially setting up a standoff with international powers.

President Bah Ndaw and Prime Minister Moctar Ouane were taken to a military base outside the capital on Monday after a cabinet reshuffle in which two officers lost their posts.

The intervention led by Vice President Assimi Goita has jeopardized Mali’s transition back to democracy after a coup in August overthrew former president Ibrahim Boubacar Keita. It has provoked international condemnation and raised fears that a political crisis in Bamako could affect regional security.

Goita, a colonel, also orchestrated last year’s coup. He has promised that elections planned for next year will go ahead.

The resignations came as a delegation from the Economic Community of West African States (ECOWAS) visited Mali to press the military to back down.

During a meeting late on Tuesday with Goita, the delegation, led by former Nigerian President Goodluck Jonathan, raised the possibility of sanctions against the officers responsible for the takeover, according to a military official who was present.