A spokesperson for the government of Gabon has said the political situation in the country is "under control", following an attempted coup.
Guy-Bertrand Mapangou told the BBC that four of the rebels had been arrested by the authorities. A fifth was on the run.
Junior officers claimed they seized power "to restore democracy" in oil-rich Gabon, where the ailing leader's family has ruled for 50 years.
Tanks and armed vehicles could be seen in the capital Libreville.
Current leader Ali Bongo succeeded his father Omar Bongo as president in 2009. He narrowly won re-election in 2016 in a poll marred by violence and accusations of fraud.
The five soldiers took control of the national radio station at 04:30 local time (03:30 GMT) to read a short statement announcing a "National Restoration Council".
In a video circulating on social media, three young soldiers can be seen in a radio studio wearing military fatigues and holding guns.
Lt Kelly Ondo Obiang, who said he represented a group called the Patriotic Movement of the Defence and Security Forces of Gabon, specifically appealed to young people to "take charge of their destiny".
The insurgents called on soldiers to take control of the transport system, ammunition reserves and airports "in the interests of the nation".
The BBC's Firmain Eric Mbadinga said the coup attempt came as a huge surprise. The army has always been seen as loyal to the Bongo family, he said, because it is dominated by the presidential guard, who mostly come from Mr Bongo's home region.
Most of the capital remains calm, an eyewitness told the Reuters news agency.
Ali Bongo succeeded his father Omar Bongo as president in 2009. He narrowly won re-election in 2016 in a poll marred by violence and accusations of fraud.
Mr Bongo, who has been out of the country for two months, reportedly suffered a stroke in October and received treatment in Morocco.
'Pitiful sight'
He sought to put an end to the rumours about his health with a televised New Year message in which he said he was feeling fine.
Soldiers said they had been disappointed by the message, calling it "a pitiful sight" and a "relentless attempt to cling onto power."
"It reinforced doubts about his ability to assume the responsibilities of his role as President of the Republic", said Lt Kelly Ondo Obiang, the leader of the so-called Patriotic Movement of the Defence and Security Forces of Gabon.
He specifically appealed to young people to "take charge of their destiny".
The insurgents called on soldiers to take control of the transport system, ammunition reserves and airports "in the interests of the nation".
There is no word so far from the government.
President Trump has deployed soldiers to Gabon to protect US citizens amid fears of violent protests in the neighbouring Democratic Republic of Congo following its presidential election.
- BBC