The leader of Gabon's military junta has vowed to return power to civilians after "free, transparent" elections.
However, in a speech after being sworn in as interim president, he did not give a date for military rule to end.
Gen Brice Nguema led last Wednesday's coup against Ali Bongo, toppling the president shortly after he was named winner of a disputed election.
Crowds of cheering civilians turned up at the inauguration - the coup was welcomed by many eager for change.
However, some say Gen Nguema's rule will be a continuation of the 55-year Bongo dynasty.
Ali Bongo's father, Omar, was in power for 41 years before he died in 2009 and was succeeded by his son.
The general, aged 48, spent most his career in the Bongo's inner circle and is even thought to be Ali Bongo's cousin.
At Monday's inauguration, Gen Nguema gave a defiant speech, referencing the likes of South African Archbishop Desmond Tutu, French statesman Charles Fe Gaulle and former Ghanaian leader Jerry Rawlings.
"This patriotic action will be a lesson learnt that will be taught in the books of our schools," said the new president, dressed in the red ceremonial costume of the Republican Guard.
He added that a fresh government would be formed "in a few days" and recommended new electoral legislation, a new penal code and a referendum on a new constitution.
Gen Nguema also said he had instructed the new government "to think without delay" about freeing all political prisoners.
The ceremony was broadcast live on Gabonese TV and across online platforms.
Hundreds of officials attended, including former ministers from the ousted government, who were booed by a crowd of junta sympathisers.
The opposition has said it welcomes the removal of Mr Bongo from power but has called for a speedy return to civilian rule.
The defeated presidential candidate Albert Ondo Ossa told the Associated Press that the coup was a "palace revolution", engineered by the Bongo family to retain their power.
Gen Nguema's is the latest in a series of military takeovers across West and Central Africa.
Gabon is the sixth Francophone country to fall under military rule in the last three years as former colonial power France struggles to maintain its influence on the continent.
Gabon was suspended from the African Union following the coup, which has been condemned by the UN and France.
In his inauguration address on Monday, Gen Nguema said he was "surprised" at foreign criticism of the takeover.
BBC