The junta grabbed power in Mali last August after mutinous soldiers encircled the home of the then President Ibrahim Boubacar Keita and fired shots into the air.
Mutinous soldiers arrested Mali's transitional president and prime minister on Monday, hours after a government reshuffle left out two members of the junta that had seized power in a coup nine months earlier, the African Union and the United Nations said.
A joint statement issued along with the West African regional bloc known as ECOWAS and other members of the international community called for the immediate release of President Bah N'Daw and Prime Minister Moctar Ouane, who were taken to the Kati military headquarters.
Those who signed on to the joint statement called for Mali's political transition "to resume its course and conclude within the established timeframe".
"The international community rejects in advance any act of coercion, including forced resignations," the statement said. "They emphasise that the ill-considered action taken today carries the risk of weakening the mobilisation of the international community in support of Mali."
The developments raised new alarm about whether the transitional government would be able to move ahead freely with plans to organise new democratic elections as promised by next February in Mali, where the UN is spending USD 1.2 billion a year on a peacekeeping mission.
The two leaders were sworn-in last September after the ruling military junta agreed to hand over power to a civilian transitional government under growing international pressure.
The junta had grabbed power a month earlier after mutinous soldiers encircled the home of President Ibrahim Boubacar Keita and fired shots into the air. He later resigned on national television under duress, saying he did not want blood to be shed in order for him to stay in office.
The soldiers then went on state television hours later, calling themselves the National Committee for the Salvation of the People and promising a swift return to civilian rule. However, Monday's developments appeared to throw that promise into question.
The arrests came just an hour or so after a new government Cabinet was announced. Notably, it did not include Interior Security Minister Modibo Kone or Defence Minister Sadio Camara, both junta supporters. No reason was given for their exclusion, but the move suggested mounting divisions within the transitional government.
There has been widespread concern that the upheaval in Mali over the past year has further set back efforts to contain the militants linked to al-Qaida and the Islamic State groups.
Islamic extremists took control of major towns in northern Mali after the 2012 coup. Only a 2013 military intervention led by the former colonial power France pushed extremists out of those towns. France and a UN force have continued to battle the extremist rebels, who operate in rural areas and regularly attack roads and cities.