Libreville - Ali Bongo is set to be sworn in as Gabon's president for a second seven-year term, his office has announced, three days after his election victory was controversially validated by the Constitutional Court following allegations of fraud.The lack of details regarding the ceremony prompted a wave of criticism from the opposition, which has accused Bongo of "stealing" the vote."You don't get sworn in unceremoniously in secret," said Jean-Gaspard Ntoutoume Ayi, spokesperson for Bongo's main rival Jean Ping. Bongo's victory in the August 27 vote was confirmed on Saturday by the country's top court, which dismissed opposition claims of voter fraud. Violence initially erupted on August 31 after Bongo, 57, was first declared the winner. Demonstrators set the parliament ablaze and clashed with police, who arrested more than 1 000 people. 'Miscarriage of justice' Opposition figures say more than 50 people were killed, but authorities disputed that claim, saying that just a handful of people had died in the violence.Ping, 73, who came in second in the vote, rejected the court's ruling as a miscarriage of justice and declared himself "president elect". A career diplomat and a former top official at the African Union, he had filed a legal challenge after Bongo was declared the winner by a slender margin of fewer than 6 000 votes. Responding to the criticism, Bongo told Al Jazeera he had little interest in the opinions of the international community."The international community does not cast a vote here, Gabonese people do. So, I am accountable to them," Bongo said. Bongo took over from his father, Omar, who ruled Gabon for 41 years until his death in 2009.Cameroon's President Paul Biya, who is 83 and has held office since 1982, wrote to Bongo on Monday voicing his "warm congratulations" and wishing him "success in the accomplishment of (his) new mandate." "In the delicate period which Gabon is going through, I want to express to you my full encouragement and hope passionately that dialogue and calm will predominate between all the parties," Ouattara wrote in a statement.