Army and police have been deployed across Libreville, the capital of Gabon, as the West African nation braces itself for the hotly contested results of a presidential election in which both candidates have already declared victory. Analysts in the African oil producer had expected opposition candidate Jean Ping to win, ending the 50-year-rule in Gabon of the Bongo dynasty.

However, as the country's electoral commission sits in a closed door session, having already missed their deadline to announce the result on Tuesday evening (30 August), fears have been raised of rioting in Liberville.

Violence greeted the disputed electoral victory of incumbent Ali Bongo in 2009. Gabon's current president replaced his father Omar Bongo as leader following his death in the same year

The younger Bongo has faced a surprisingly strong challenge from Ping, a former foreign minister after a coalition of opposition parties united behind him.

Ping, so confident of his victory, said on Sunday after polls closed: "I am elected. I am waiting for the outgoing president to call me to congratulate me." Ping has also predicted a margin of victory of 10 percent of the popular vote, Reuters reported.

At the same time, Bongo has indicated he expects a win. "Be confident, great things await us," he said adding he was expectantly awaiting the announcement of the national election commission.

The Guardian reported that the campaign between the two men, who are practically family – Ping is the father of two of Bongo's nephews – has been characterised by bitter smears.

Ping had accused Ali being an adopted Nigerian refugee and of no relation to his father. He has also accused Bongo of genocide, theft and being a pyromaniac.

Premature election predictions by France's Socialist party have also given rise to accusations of interference against Gabon's former colonial ruler. "First estimates indicate that the outgoing president, Ali Bongo, will be beaten by Jean Ping ... A changeover would be a sign of good democratic health and an example," the ruling French party said in a statement.