Nominations for Nigeria's forthcoming presidential elections are under way and political parties are now free to hold primaries to select candidates, the electoral commission confirms.

It comes at a time when the governing APC party is grappling with a wave of mass defections by senior politicians.

The political parties in Nigeria have until 7 October to present candidates for the February 2018 general election.

So far only President Muhammadu Buhari has declared his plan to stand for the governing APC party, seeking what would be his second term in office.

But a dozen aspirants from the main opposition party, the PDP, are hoping to be picked as presidential candidate to challenge Mr Buhari.

They include recent defectors Senate President Bukola Saraki, former Vice-President Atiku Abubakar and a former governor of Kano state, Rabiu Kwankwaso.

Another potential challenger to Mr Buhari is the current governor of the north-eastern state of Gombe, Ibrahim Dankwambo.