The government in Gabon, led by Africa's longest ruling leader, has called upon opposition leaders to accept the results of a recent presidential election following a day of clashes. Two opposition candidates say they won't back down from their claims that last Sunday's vote was rigged in favor of the incumbent Omar Bongo.

Gabonese authorities are asking opposition leaders to renounce all violence. Members of President Omar Bongo's elite republican guard were reinforcing strategic points throughout the capital, Libreville, Friday.

More than 20 people were said to have been arrested Thursday, following clashes with security forces.

A strong police presence has been deployed since official results from last Sunday's presidential election gave President Bongo nearly 80 percent of the total votes. But opposition leaders quickly cried foul, accusing Mr. Bongo and Gabonese authorities of committing massive fraud.

International observers declared the vote free and fair, but none came from major organizations seen as rigorous in vetting African elections.

Third place candidate Zacharie Myboto, a former close associate of Mr. Bongo, has said he will not back down from his claims the election was rigged.

The Gabonese people are sick of the regime, he says. They don't accept having elections under these conditions. It is not a problem of opposition leaders, he says, it is a problem for the Gabonese people.

President Bongo has ruled Gabon for the last 38 years.

Mr. Myboto, who has teamed up with the candidate who finished second, Pierre Mamboundou in his protest, says a solution to the current impasse will not be found in brutality and crackdowns.

He says any real solution must have roots in a respect for human rights.

Tensions surrounding the declaration of the results, says independent journalist Desire Ename, have paralyzed much of the capital.

"The presence of police in the streets, its a way to have people stay at home," said Desire Ename. "Can you imagine that it is almost one week that children don't go to school? All the schools in Libreville are almost closed."

Mr. Ename says, so far, the protests against Mr. Bongo's victory have been isolated, largely spontaneous events.

"It is only in some areas, in some places," he said. "People who don't agree with what's going on at all. These are not really movements that are organized by the opposition members or leaders. I think that it will continue."

Gabon has remained relatively stable under Mr. Bongo's rule, as regional neighbors Congo-Brazzaville, Angola, and the Democratic Republic of Congo have descended into civil war. Despite timber and oil wealth, the lightly populated country has suffered from rampant corruption and remains underdeveloped.