New Delhi, Oct. 15 -- Cameroon opposition candidate Issa Tchiroma Bakary claimed victory Tuesday in the Oct. 12 presidential election ahead of the release of official results, urging President Paul Biya, the world's oldest president, to concede.

"Our victory is clear, it must be respected," Tchiroma said in a video statement on Facebook, calling on Biya to "accept the truth of the ballot box" or "plunge the country into turmoil." He said he will share a detailed report of the votes by region in the coming days.

Elections Cameroon, the independent body in charge of overseeing the poll, and the constitutional court have not yet announced any results. Official results are expected at the latest by Oct. 26.

Analysts have predicted a victor...