"We have decided, after having taken the president, to dissolve the constitution," said a uniformed officer flanked by soldiers toting assault rifles in a video sent to AFP.

The officer also said that Guinea's land and air borders have been shut and the government dissolved.

But the situation remained unclear as Conde's government also released a statement saying that an attack on the presidential palace by special forces had been "repulsed".

Guinea -- one of the world's poorest countries despite boasting significant mineral resources -- has long been beset by political instability.

Earlier on Sunday, residents of the capital Conakry's Kaloum district, the government quarter, reported hearing heavy gunfire.

Speaking on condition of anonymity for their safety, they reported seeing a number of soldiers on the streets who called on residents to return to their homes and stay there.

A Western diplomat in Conakry, who also declined to be named, said the unrest started after the dismissal of a senior commander in the special forces -- provoking some of its highly trained members to rebel and occupy the presidential palace.

AFP was unable to independently confirm this account.

The officer in the putsch video released later on Sunday, wearing sunglasses and a red beret, said that the army had taken action because of government dysfunction, corruption and "the trampling of citizens' rights," among other reasons.

The apparent coup comes amid a long period of political tension in Guinea, first spurred by Conde's highly contested bid for a third presidential term last year.

The day before the presidential election last year, the military blocked access to Kaloum after an alleged military rebellion east of the capital.

Conde, 83, also survived an assassination attempt in 2011.

-- Violent elections --

The most recent presidential poll in the nation of some 13 million people, in October 2020, was violently disputed and also marred by accusations of electoral fraud.

Conde won a controversial third term in that poll, but only after pushing through a new constitution in March 2020 that allowed him to sidestep the country's two-term limit.

Dozens of people were killed during demonstrations against a third term for the president, often in clashes with security forces. Hundreds were also arrested.

Conde was then proclaimed president on November 7 last year -- despite his main challenger Cellou Dalein Diallo as well as other opposition figures calling the election a sham.

After the poll, the government launched a crackdown and arrested several prominent opposition members for their alleged role in abetting electoral violence in the country.

A former opposition leader himself who was at one point imprisoned and sentenced to death, Conde became Guinea's first democratically-elected leader in 2010 and won re-election in 2015.

Hopes of a new political dawn in the former French colony have withered, however, and he has been accused of drifting into authoritarianism.