By NBF News

Under the constitution, Rose Francine Rogombe, an ally of Mr Bongo, must organise elections within 45 days.

On Thursday, Mr Bongo's body will be repatriated from Spain where he had been undergoing medical treatment.

Access to the internet in the oil-rich nation remains cut off, but the state's borders have been reopened.

Ms Rogombe was sworn in at the International Conference Centre in the capital, Libreville, on Wednesday morning, a day after her appointment was confirmed by the constitutional court.

The death of the 73-year-old president, who was Africa's longest-serving leader, was announced on Monday.

The government said Mr Bongo, who had led Gabon since 1967, had died of a heart attack, hours after saying he was alive and well.

It emerged in May the president was being treated in a Barcelona clinic, amid unconfirmed reports he had cancer.

On Thursday the late president's body will arrive back in the country where it will lie in state at the presidential palace in the capital.

He will be buried at Franceville in the Bateke region of his birth in south-east Gabon on Thursday of next week.

On Tuesday, Mr Bongo's son – Defence Minister Ali-Ben Bongo – appealed for calm following his father's death.

Observers say the ruling Gabonese Democratic Party (PDG) has been deciding who should succeed him, with his 50-year-old son a leading contender.

The BBC's Linel Kwatsi, in Libreville, says the security forces are keeping a low profile on the capital's streets, which are quieter than usual.

Gabon Telecom says the internet, cut since Sunday, has been hit by an optical fibre technical fault.

But many believe the government has ordered the company to take Gabon off-line so as to control access to information in the aftermath of the president's death.

The city's mayor has banned large gatherings and ordered nightclubs and bars to close, while security forces are on patrol.