At least two people were injured as heavy gunfire broke out near the presidential palace in Guinea's capital Conakry on Sunday morning, while military vehicles patrolled the streets, witnesses said and videos shared on social media showed, Trend reports citing Reuters.
It was not clear who was exchanging fire.
A senior government official said 83-year-old President Alpha Conde was unharmed but gave no further details.
A military source said the gunfire involved angry members of the special forces, an elite army corps. The source did not say what caused the anger.
Another military source said the only bridge connecting the mainland to the Kaloum neighbourhood, which houses most of the ministries and the presidential palace, had been sealed off and many soldiers, some heavily armed, were posted around the palace.
Three witnesses told Reuters they saw two civilians with gunshot wounds.
"I see groups of soldiers heading towards the presidency. There has been a lot of shooting," said Ousmane Camara, a resident of Kaloum.