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.
The unrest coincides with calls for more protests to demand that the president resign.
What do we know about the mutiny?
It is led by Col Malick Diaw – deputy head of the Kati camp – and another commander, Gen Sadio Camara, BBC Afrique’s Abdoul Ba in Bamako reports.
After taking over the camp, the mutineers marched on the capital.
In the afternoon they stormed Mr Keïta’s residence and arrested the president and his prime minister – who were both there.
The reason for the move is unclear, as is the number soldiers taking part in the mutiny. Some reports say it was fuelled by a pay dispute.
Kati camp was also the focus of a mutiny in 2012 by soldiers angry at the inability of the senior commanders to stop jihadists and Tuareg rebels taking control of northern Mali.
Footage from AFP news agency showed a building owned by the justice ministry in Bamako ablaze on Tuesday.