Mali President Ibrahim Boubacar Keïta has been arrested by mutinying soldiers, a government spokesman has confirmed to the BBC.
Prime Minister Boubou Cissé has also been arrested, despite earlier appeals for “brotherly dialogue”.
The apparent coup attempt in the West African nation began with gunfire at a key military camp near the capital, Bamako, on Tuesday morning.
In the city young men set a government-owned building on fire.
It comes hours after disgruntled junior officers detained commanders and took control of the Kati camp, about 15km (nine miles) from Bamako.
The mutiny has been condemned by regional group Ecowas, the African Union and former colonial power France.