Members of Burkina Faso's presidential guard have seized control of the government after taking the interim president and other leaders hostage.
The coup comes just weeks before elections.
Lieutenant-Colonel Mamadou Bamba appeared on national television on Thursday (local time) to declare a new "National Democratic Council" had put an end "to the deviant regime of transition" in the west African state and Burkina's interim president had been stripped of his powers.
"The National Transition Council has been ... dissolved .... Wide-ranging talks are being held to form a government ... to lead to inclusive and peaceful elections," he added.
Interim parliament speaker Cheriff Sy told the French radio station RFI that what was happening was "clearly a coup" and called on the people to "immediately rise up" in response.
Demonstrations against the coup are taking place, with soldiers firing shots to disperse protesters arriving on the central Place de la Revolution, witnesses said.
On Wednesday, members of the presidential guard who are loyal to ousted ex-leader Blaise Compaore burst into a cabinet meeting and seized President Michel Kafando, Prime Minister Isaac Zida and two ministers.
UN Secretary-General Ban Ki-moon and the European Union have condemned the leaders' detention and called for their immediate release.
"The EU calls for the immediate release of those detained and respect for the political transition and the national interest," EU foreign affairs head Federica Mogherini said in a statement.
She said the 28-nation EU stood with the United Nations and the African Union in condemning events in the capital Ouagadougou.
The transitional period that was due to lead to October 11 elections following the fall of president Blaise Compaore in October 2014 has been cancelled, said a spokesman for the Presidential Security Regiment, whose name was not known.
Kafando, Zida and two other ministers were then taken to a military base inside the presidential compound, radio broadcaster Omega FM reported before soldiers closed the station on Wednesday.
Compaore was toppled in October 2014 and fled into exile in Ivory Coast after an uprising triggered by his attempt to extend his 27-year rule.