At least 10 people have been killed and more than 100 injured in protests sparked by the coup.
Troops loyal to Burkina Faso’s government have massed in the capital and told soldiers behind a coup to disarm and surrender or face attack, setting up a showdown over control of the country.
The deadline, which expired at 10am GMT on Tuesday, came as talks between the army and the elite presidential guard continued in the capital, Ouagadougou.
In an apparent olive branch, the coup leaders released interim prime minister Yacouba Isaac Zida, who had been held hostage since the revolt began, his adviser and another loyalist officer said.
Ex-spy chief General Gilbert Diendere and his presidential guard rebelled on Wednesday, raiding a cabinet meeting and detaining the president and other ministers.
The release of Zida came hours after army soldiers entered Ouagadougou without resistance.
Diendere, who is a close ally of deposed long-term president Blaise Compaore, already vowed to hand over power to a civilian transitional government.
Army leaders began surrender talks late on Monday with the elite presidential guards that staged the coup.
“All units [of the army mobilised on Monday to march on the capital] reached Ouagadougou” overnight, Colonel Serge Alain Ouedraogo, deputy head of the Burkinabe police, told the AFP news agency.
“We must now secure the surrender of the [coup leaders] without gunfire or bloodshed,” he said.
At least 10 people have been killed and more than 100 injured in protests sparked by the coup, which came just weeks before what would have been the first elections since Compaore was ousted in a popular revolt last October after trying to extend his 27-year grip on power.
Diendere on Monday apologised to the nation and said he would hand over control to a civilian transitional government after the military warned that its forces would converge on the capital and forcibly disarm the soldiers behind the power grab.
He said his presidential guard unit “confirms our commitment to giving power back to civilian authorities”, in a communique issued to journalists. That was one of the key conditions of a draft agreement that resulted from weekend negotiations with regional mediators, but it had been unclear until his announcement whether the coup leaders would abide by those terms.
After the announcement, Al Jazeera’s Nicolas Haque, reporting from Ouagadougou, said people were taking to the streets by the military headquarters to celebrate what they hoped meant the end to the coup and the chance of elections later this year.