Election officials compiled results in Gabon on Sunday as representatives of the incumbent president and his most prominent challenger predicted victory.

President Ali Bongo Ondimba is vying for a second seven-year term. Bongo became president after the death of his father, who ruled for more than 40 years.

His strongest challenger is Jean Ping, a former chair of the African Union Commission.

Bongo's spokesman Alain-Claude Bilie-By-Nze said late Saturday that the president was "en route to a second term." He also said fraud had been noted in some polling stations where opposition representatives were first to arrive, though he did not provide details.

However Ping's supporters said their candidate was clearly the winner and accused Bongo's team of trying to create instability.

Provisional results are expected Tuesday.