Demonstrators in Gabon clashed with police and set part of the parliament building on fire on Wednesday as anger boiled over among opposition supporters at President Ali Bongo's re-election in polls that his main rival, Jean Ping, claimed to have won.
Opposition members of the Central African oil producer's electoral commission rejected Saturday's first-past-the-post election result, which would see the Bongo family's nearly half-century in power extended another seven years.
The election followed a bitter campaign.
Gabon's economic troubles, caused by falling oil output and prices, have led to budget cuts in one of Africa's richest nations and fuelled opposition charges that its 1.8 million people have struggled under Bongo's leadership.
France, the United States and the European Union all urged calm and called upon Gabonese authorities to release the results of individual polling stations for greater transparency, while the United Nations also urged restraint.
Bongo won 49.80 percent of votes, compared to 48.23 percent for Ping, with a turnout of 59.46 percent, according to results announced region by region by Interior Minister Pacome Moubelet Boubeya.
"This victory by such a tight score obliges ... each of us to respect the verdict of the ballot box and our institutions," Bongo said in the text of a victory speech distributed to reporters.
"Our country is advancing and that advance must take place with the unity and peace so dear to the Gabonese people."
Soon after the result was announced on state-owned television, riot police fired teargas in clashes with around 100 opposition supporters in one neighbourhood in the capital Libreville, according to a Reuters witness.
Police and soldiers, meanwhile, were stationed at most crossroads and petrol stations.
Protesters entered the grounds of Gabon's parliament building, the National Assembly, late in the afternoon.
"The demonstrators entered from the back and set fire to the National Assembly ... Part of the building is on fire," said another witness, who asked not to be named out of fear of reprisal.
Firemen were attempting to put out the blaze, he said. But as night fell the flames remained visible from a distance.
Several Libreville residents said social media, including Facebook and Twitter, were no longer functioning.
Gabon's main cities had been on edge since Tuesday, with residents stockpiling food ahead of the expected announcement, which was later postponed by one day.
"In this election, we committed ourselves to liberating our country. And that is the choice that was clearly expressed by the Gabonese people," Ping said in a statement released late on Wednesday in which he rejected the election result.
He accused ruling party members of the electoral commission of inflating turnout figures and votes in favour of Bongo in order to hand victory to the president. The claim could not immediately be independently verified.
Commission members belonging to the opposition abstained from a vote that validated the election result.
Ping's party had earlier said its tally showed their candidate won 59 percent of the vote versus 38 percent for Bongo, with only one province left to count, a claim the government condemned as an effort to destabilise the country.
Ali Bongo was first elected in 2009 after the death of his father Omar, who ran Gabon for 42 years. He benefited from being the incumbent in a country with a patronage system lubricated by oil largesse.
Though voting on Saturday was generally peaceful, Bongo and Ping's supporters traded accusations of fraud.
An EU observer mission sent to monitor the polls criticised a "lack of transparency" among institutions running the election and said Bongo had benefited from preferential access to money and the media.
Former colonial ruler France's foreign ministry said the manner in which the final results were announced on Wednesday was a source of concern.
"We think it is necessary to publish the results of all the polling stations. The credibility of the election as well as Gabon's international reputation are at stake," it said.
The statement was echoed by the U.S. Department of State, which urged all sides to "temper their rhetoric and encourage their supporters to remain calm". It also called upon Gabon's security forces to exercise restraint.
A spokesman for U.N. Secretary-General Ban Ki-moon said he called "on all political leaders to address their differences peacefully and to address any disputes they may have through existing constitutional and legal channels."
Ban also called on the authorities to ensure that the national security forces exercise restraint in their response to protests, spokesman Stephane Dujarric said in a statement.
Ping, a life-long political insider who has served as foreign minister and African Union Commission chairman, was a close ally of Omar Bongo and fathered two children with the late president's daughter, Pascaline.