Gabon's electorate lined up at polling stations Saturday tasked with a decision on whether to extend the 49-year rule of the Bongo family. President Ali Bongo, 57, has been in office since his father Omar - who ruled from 1967 - died in 2009.

Ali Bongo has been challenged 73-year-old Jean Ping, an ex-African Union Commission chief who has worked under the elder Bongo.

The incumbent has promised to clean up corruption and criticized the older generation of statesmen with a jibe that encompassed his political opponent as well as his own father.

"There's a risk that certain people who did so much harm to our country will come back," President Bongo had told a crowd of thousands during his last rally in the capital, Libreville.

Anxiety over Gabon's faltering resource-based economy - dragged down by the low world price of oil - was a major issue in the campaigns.

Polls were to be open for 11 hours on Saturday from 0600 to 1700 UTC. Results are not expected to come in less than 24 hours.

Despite boasting one of Africa's highest per capita incomes at around 7,415 euros ($8,300), a third of Gabon's population live in poverty, and unemployment among young people stands at 35 percent, according to the World Bank.

Until recently, the president was far and away the favorite, largely because several prominent politicians had joined the race, diluting the opposition's ticket. But protracted talks led all the key challengers to pull out and support Jean Ping.

The campaign has been acrimonious. Both sides have accused each other of trying to buy voter cards, in some cases for as little as 10,000 CFA francs (15.25 euros) a piece.

About 628,000 of Gabon's 1.8 million inhabitants are eligible to vote. The result will be decided in a single round by a simple majority.

jar/jm (AFP, dpa)