Army officers who seized power in a coup in Gabon on Wednesday have named General Brice Oligui Nguema as the country's transitional leader.

Gen Nguema was earlier carried triumphally through the streets of the capital Libreville by his troops.

The deposed President, Ali Bongo, has appeared in a video at his home, calling on his "friends all over the world" to "make noise" on his behalf.

The former French colony is one of Africa's major oil producers.

Mr Bongo's overthrow ended his family's 55-year hold on power in the Central African state.

Army officers appeared on TV in the early hours of Wednesday to say they had taken power.

They said they had annulled the results of Saturday's election in which Mr Bongo was declared the winner but which the opposition said was fraudulent.

The officers also said they had arrested one of Mr Bongo's sons for treason.

Within hours, generals met to discuss who would lead the transition and agreed by a unanimous vote to appoint Gen Nguema, former head of the presidential guard.

Gen Nguema told France's Le Monde newspaper that Gabonese people had had enough of Ali Bongo's rule, and that he should not have run for a third term.

"Everyone talks about this but no one takes responsibility," he said. "So the army decided to turn the page."

Crowds in Libreville and elsewhere celebrated the army's declaration.

But the coup was condemned by the UN, the African Union and France, which had close ties to the Bongo family.

The US state department urged Gabon's military to "preserve civilian rule" and urged "those responsible to release and ensure the safety of members of government". The UK condemned the "unconstitutional military takeover" of power.

There has long been simmering resentment of the Bongo family - it ruled Gabon for almost 56 years - and there has been public discontent over broader issues such as the cost of living.

"At first I was scared, but then I felt joy," a resident of Libreville, who requested anonymity, told the BBC. "I was scared because of the realisation that I am living through a coup, but the joy is because we've been waiting for so long for this regime to be overthrown."

Gen Nguema, 48, was absent from the first three statements read out by senior army officers on national television to announce the coup.

But he was named transitional leader soon after, and was carried through the streets in jubilant scenes.

He was aide-de-camp to the ousted leader's father, Omar Bongo, who ruled for almost 42 years until his death in 2009.

A former close colleague told AFP news agency that Gen Nguema had been extremely close to Omar Bongo, serving him from 2005 until his death in a Spanish hospital.

Under Ali Bongo he first worked as a military attache at Gabon's embassies in Morocco and Senegal.

But in 2018 he was made intelligence chief under the elite republican guard - Gabon's most powerful army unit - replacing Ali Bongo's half-brother Frederic Bongo, before getting promoted to general.

As in previous general elections in Gabon, there were serious concerns about the process in Saturday's vote.

Main opposition candidate Albert Ondo Ossa complained that many polling stations had lacked ballot papers bearing his name, while the coalition he represented said the names of some of those who had withdrawn from the presidential race had still been on the ballot sheet.

Both of Mr Bongo's previous wins were disputed as fraudulent by opponents. This time, controversial changes were made to voting papers just weeks before election day.

In 2018, he suffered a stroke which sidelined him for almost a year and led to calls for him to step aside.

The following year, a failed coup attempt saw mutinying soldiers sent to prison.