The main opposition in Nigeria on Monday rejected provisional presidential results declared by the electoral commission showing the ruling party in the lead, accusing the two of being in collusion.

The People's Democratic Party (PDP) said the initial results announced by the Independent National Electoral Commission (INEC) were unacceptable, alleging the ruling All Progressives Congress (APC) and state security agents were working with the commission to manipulate the vote.

The PDP chairman Uche Secondus told journalists that the results are incorrect and unacceptable to their party, as officials of the APC working with INEC have decided to alter results to affect their people.

Nigeria held presidential elections last Saturday, which were set to be last of last Saturday.