Soldiers who staged an uprising in Guinea's capital on Sunday said in a short broadcast on the West African nation's state television that they have dissolved the constitution and the government in an apparent coup.

An unidentified soldier, draped in Guinea's national flag and surrounded by eight other armed soldiers, said they planned to form a transitional government and would give further details later.

The soldier spoke after videos shared on social media - which Reuters could not immediately authenticate - showed President Alpha Conde surrounded in a room by army special forces.

The defence ministry said the attemped insurgency had been put down.

"The presidential guard, supported by the loyalist and republican defence and security forces, contained the threat and repelled the group of assailants," it said in a statement.

"Security and combing operations are continuing to restore order and peace."

Earlier, videos shared on social media showed military vehicles patrolling Conkary's streets and one military source said the only bridge connecting the mainland to the Kaloum neighbourhood, which houses the palace and most government ministries, had been sealed off.

Many soldiers, some heavily armed, were posted around the palace, the source added.