Large crowds of mourners gathered at Libreville airport
Up to 10,000 Gabonese have turned out to see the body of the late President Omar Bongo arrive back home from Spain, where he died on Monday.
Mourners lined the route from the airport in the capital Libreville as the car carrying the leader's coffin drove slowly through the city.
His body is to lie at the presidential palace ahead of the burial next week.
The senate's speaker was sworn in on Wednesday as interim head of state. Elections must be held within 45 days.
Earlier, a small funeral ceremony was held at Barcelona airport before the Spanish Air Force plane took off for West Africa, reports the AP news agency.
Mr Bongo, who was in power for nearly 42 years, is to be buried at Franceville in the Bateke region of his birth in south-east Gabon on Thursday of next week.
Interim leader Rose Francine Rogombe must organise elections in 45 days
At least 10 heads of state, including French President Nicolas Sarkozy, are expected to attend the funeral.
Under Mr Bongo, Gabon retained close economic and political ties to France, its former colonial power.
Politicians, diplomats and military officials were on the tarmac to receive the coffin, draped in the national flag, with full honours on Thursday.
Mr Bongo's daughter and cabinet chief, Pascaline, reportedly fell sobbing into the arms of Congo's President Denis Sassou-Nguesso, who was also Mr Bongo's father-in-law.
Gabonese journalist Linel Kwatsi says thousands of people, many in black clothing or wearing T-shirts with Mr Bongo's image, turned out along the waterfront and waved at the vehicle bearing the late leader's body as it cruised past.
He says the anxiety that overshadowed the country as news of the president's death emerged is vanishing.
There is relief that the mechanisms of democracy appear to be working and that fears of a coup have proved unfounded, he adds.
The hope now is that interim leader, Rose Francine Rogombe, an ally of Mr Bongo, will organise fair presidential polls.
The ruling Gabonese Democratic Party (PDG) has been deciding who should succeed the late president, with his 50-year-old son, Defence Minister Ali-Ben Bongo, tipped as a leading contender.
Ms Rogombe, 66, a lawyer and ruling party member dubbed "the iron lady", is constitutionally ineligible from standing in the presidential poll.
Likely opposition candidate Pierre Mamboundou - leader of the Union of the Gabonese People - has called on citizens to back Ms Rogombe while she organises polls to help "guarantee transparency during the vote".
It emerged last month that Mr Bongo was being treated in a Barcelona clinic, amid unconfirmed reports he had cancer.
The government said on Monday the 73-year-old had died of a heart attack, hours after saying he was alive and well.
Libreville's mayor has banned large gatherings and ordered nightclubs and bars to close, while security forces have been on patrol.