Cameroon's 92-year-old president has won a controversial eighth term, in a fiercely disputed election.

Paul Biya, who is the world's oldest head of state, won 53.7% of the vote, compared to 35.2% of opposition leader Issa Tchiroma Bakary, the Constitutional Council declared.

Before the announcement, Tchiroma Bakary - a former Biya ally - insisted he had won the election, but the ruling Cameroon People's Democratic Movement (CPDM) dismissed his claim.

The election, held on 12 October, has been marred with deadly violence, and in recent days, hundreds of Tchiroma Bakary's supporters have defied protest bans in several cities, and clashed with security forces.

On Sunday, at least four people were killed during protests in Cameroon's economic capital of Douala. The regional governor, Samuel Dieudonné Diboua, said police posts had come under attack and security forces had defended themselves.

The unrest continued on Monday, when a number of people were shot dead near Tchiroma Bakary's residence in the city of Garoua, a local journalist on the scene reported.

At least 10 petitions alleging electoral malpractice have been rejected by the Constitutional Council.

Residents in Yaoundé have voiced their opinions on Biya's controversial victory. We are at the beginning of another nightmare, said one resident. Another urged acceptance for peace's sake.

Political analysts warn that Cameroon could face significant turmoil if the election results are viewed as illegitimate by the population.

In response, Biya's party celebrates his victory as a sign of greatness and hope, even as he remains publicly silent.