Mutineering soldiers said on Tuesday that they had detained Mali’s President, Ibrahim Boubacar Keita, and Prime Minister Boubou Cisse.
Witnesses and officials said soldiers seized an important army base in the town of Kati, near the capital Bamako, on Tuesday morning.
“We can tell you that the president and the prime minister are under our control,” the mutineers' leader told AFP.
He said the leaders had been “arrested” at Mr Keita’s residence in Bamako.
Another military official said the president and prime minister were in an armoured vehicle en route to Kati.
Hours earlier, Mr Cisse called for talks with the soldiers who have sparked fears of a coup.
“The government is calling for calm and makes itself available ... to engage in fraternal dialogue in order to remove all misunderstandings,” he said.
Mr Cisse admitted that the soldiers might have legitimate grievances.
France condemned the troops’ actions.
“France has become aware of the mutiny that has taken place today in Kati, Mali. It condemns in the strongest terms this serious event,” French Foreign Minister Jean-Yves Le Drian said.
Mr Le Drian urged the soldiers to return to their barracks without delay.
The developments on Tuesday bore a resemblance to the events leading up to the 2012 military coup, which led to years of chaos in Mali.
Mr Keita, elected in 2013, is facing mounting pressure to step down as his popularity falls.
Regional mediators urged him to share power in a unity government but that was swiftly rejected by opposition leaders, who said they would accept nothing but Mr Keita’s removal.
His government has been criticised for its handling of the militant insurgency engulfing the country, which was once praised as a model of democracy in the region.