By Linel Kwatsi and Media Coulibaly

LIBREVILLE, Sept 3

Soldiers clashed with opposition supporters in the streets of Gabon's capital on Thursday after Ali Ben Bongo, son of long-time ruler Omar Bongo, was declared the winner of a disputed presidential election.

A rival candidate was wounded in the unrest in Libreville, while French media reported rioting in Port Gentil city in the central African nation's oil zone. French oil giant Total reported no damage to its premises there.

"This is just what happens in Africa," Angel Nzeg, a female opposition supporter in Libreville said of the chaos surrounding the poll announcement. "What do you want us to do?" she said.

Ex-defence minister Ben Bongo, 50, scored 41.73 percent of the vote, the interior ministry announced, ahead of ex-interior minister Andre Mba Obame and Pierre Mamboundou, both of whom disputed results that gave them around 25 percent each.

"We condemn these results. It is a constitutional coup d'etat," said Richard Mombo, secretary general of veteran opposition figure Mamboundou's Union of Gabonese People (UPG) party.

Mombo told Reuters by telephone that Mamboundou had been "seriously injured" in clashes with security forces in the capital earlier but gave no details of his condition.

A Reuters witness touring the streets shortly after security forces broke up the demonstrations said streets of downtown Libreville were virtually empty.

Ben Bongo's rivals accuse him of rigging the result to ensure a dynastic transfer of power from his father, who brought stability during nearly 42 years of rule but faced accusations he used petrodollars to enrich family and friends.

"I want to be president of all the Gabonese," Ben Bongo declared on TeleAfrica, the Bongo family's television station.

Bloodstains

With bloodstains on his head, Libreville local Pascal Minko said he was knocked to the ground by something that hit him as riot police used tear gas launchers.

"I really didn't expect anything like that at all," he said.

Ben Bongo said before the results that authorities would deal firmly with any street disorder.

In Port Gentil, an unnamed resident was quoted by French state radio France Info as saying prisoners freed from a local jail were roaming the streets and had set fire to a petrol station.

"There are thousands of people. There is the opposition but it is not just the opposition. Everyone is taking advantage of this, not just the prisoners," it quoted him as saying.

The dispute comes after polls this year in Niger, Congo Republic and elsewhere in the region where incumbent leaders have been accused of rigging results to stay in power.

Observers and financial markets have played down the risk of major instability in Gabon but some unrest was expected given the dispute over the result.

"The result is not unexpected, Ali Ben Bongo had seemed to be groomed by his father, but there has been a groundswell of opposition. There is definitely a sense on the ground that people didn't want to see a Bongo dynasty," said Kissy Agyeman-Togobo of IHS Global Insight.

Assuming order is restored, little change was expected in the business-friendly policies espoused by the late president, whose son now faces the challenge of replacing Gabon's dwindling oil reserves with alternative revenues.

"We would expect his policies to be broadly in line with his father's, so relatively friendly to foreign investors, both in the financial sector and oil industry. It's relatively good news for foreign businessmen and investors," said Richard Segal, a specialised debt broker with Knight Libertas.

Gabon hosts oil firms including France's Total and U.S.-based Vaalco, and is one of the few sub-Saharan countries to have launched a Eurobond..

"Today some protesters came close to the big Total Gabon concession in Port Gentil and there was some material damage nearby. The buildings of the concession itself were not damaged," a Total spokeswoman in Paris said.

-Reuters