Gabon's electoral commission has begun to review the votes for Saturday's presidential election before announcing provisional results, a day later than expected.

A state television station says the review began early Wednesday after a postponement because results from all provinces were not yet in.

Security forces have fanned out across the capital of the Central African nation in anticipation of the results for the election.

Both main opposition candidate Jean Ping and President Ali Bongo Ondimba have predicted a victory.

The 73-year-old Ping, the son of a Chinese immigrant, hopes to topple a family dynasty stretching back to the 1960s. The 57-year-old Bongo came to power after his father's death.

Ping has urged Bongo to step down.

Bongo's win in 2009 sparked looting and clashes between protesters and security forces.