Vote counting is under way in Cameroon following Sunday's presidential election in which incumbent Paul Biya is seeking to extend his 43 years in power.

Biya, who at 92 is the world's oldest head of state, is being challenged by nine candidates. If he wins, it will be his eighth consecutive term in office, with the next election due in 2032.

Interior Minister Paul Atanga Nji said that voting took place "hitch-free" across the country. But there was a call for a boycott in the English-speaking regions in the west and there were reports of clashes in the north.

The final result should be known within 15 days of the vote.

In the run-up to the election there were complaints from the opposition of attempts to suppress their support.