Nigeria's top opposition candidate is urging the military not to be involved in the upcoming presidential election, saying the army "has no role to play in the conduct" of the poll.

Speaking on national television Tuesday, Atiku Abubakar criticized President Muhammadu Buhari's earlier remarks in which he ordered Nigeria's security forces to be "ruthless" with those found interfering with the voting process.

Nigeria's presidential election, initially scheduled for Feb. 16, was at the last minute postponed for a week to Feb. 23, raising political tensions. The electoral commission said it needed more time to organize a credible election.

Both the ruling party and the opposition have criticized the delay.

The race between Buhari and Abubakar appears to be tight.