Keita was arrested alongside Prime Minister Boubou Cisse in Bamako, the country’s capital.
A European diplomat had said a small number of members of the national guard “apparently angered by a pay dispute” had seized a munitions depot but were reported to have since been surrounded by other government troops.
Earlier, the Norwegian Embassy in Mali had alerted its citizens of possible unrest, advising them to stay at home.
“The embassy has been notified of a mutiny in the Armed Forces and troops are on their way to Bamako. Norwegians should exercise caution and preferably stay at home until the situation is clear,” the embassy had said a statement.
In June, opponents asked Keita, who had spent two out of his five years second term in office, to step down.
A resistance group, M5, also insisted that the constitutional court must be dissolved, while the president must resign, before peace can return to the country.
The crisis had erupted after the court nullified results of 31 parliamentary seats in the country’s polls, awarding victory to some other contenders, which the resistance group said was at the instigation of Keita.
On July 10, riots led to the killing of some protesters by security agents.
Ex-President Goodluck Jonathan met with President Muhammadu Buhari at Aso Rock to brief him on the situation in Mali earlier in the day.
The Economic Community of West African States (ECOWAS) had appointed Jonathan as its special envoy on Mali crisis.