LIBREVILLE, Gabon — Voting closed Saturday evening in Gabon, where the president is vying for re-election and voters weighed whether to maintain a family dynasty that stretches back to the 1960s.

Ali Bongo Ondimba took power in 2009 following the death of his father, Omar Bongo, who ruled the oil-producing country of about 1.5 million people for more than 40 years. In his campaign Bongo has touted his efforts to diversify Gabon’s economy and accused the opposition of inciting violence.

The most formidable challenge among nine opponents comes from Jean Ping, a former chair of the African Union Commission who managed to get several other aspirants to rally around his candidacy.

Bongo’s bid for a second seven-year term is aided by the fact that Gabon does not have a runoff system, meaning he does not have to receive more than 50 percent of the votes in the first round to win.

After casting his ballot, the president told reporters he was confident the process would go smoothly and said he hoped “all Gabonese can vote in calm and serenity.”

Ping, meanwhile, said there had been a “total rejection” of Bongo and warned his supporters to be on guard against fraud.

The tense campaign has featured efforts to get Bongo’s candidacy annulled based on claims he was born in Nigeria and therefore is ineligible to be president — claims Bongo has dismissed as unfounded.

Bongo’s victory in 2009 sparked looting and clashes between protesters and security forces. The office of U.N. Secretary-General Ban Ki-moon on Friday issued a statement calling on candidates to avoid “any acts of incitement or the use of inflammatory statements.”

More than 600,000 voters are registered to participate. Voting was scheduled to end at 6 p.m., though polling stations that opened late could remain open to accommodate voters waiting in line, according to an announcement by Rene Aboghe Ella, president of the electoral commission.

Provisional results are expected early next week.