Nigerian presidential candidates signed a pledge on Thursday to ensure peaceful elections in February, after previous ballots were marred by violence, voter intimidation and vote rigging.
President Muhammadu Buhari, who is barred by the constitution from running again, has promised free and fair elections in Africa's most populous country.
The race to succeed him officially started on Wednesday, giving candidates their longest campaign period since the end of military rule in 1999.
At a ceremony organised by the National Peace Committee (NPC) in the federal capital Abuja, main opposition candidate Atiku Abubakar, the Labour Party's Peter Obi and 15 other candidates from smaller parties appended their signatures pledging a peaceful campaign.
Ruling party candidate Bola Tinubu did not attend, although his running mate Kashim Shettima did. Shettima did not say why Tinubu was absent.
Independent National Electoral Commission chairman Mahmood Yakubu said the commission will be monitoring to ensure that "parties shun abusive, intemperate or slanderous language as well as insinuations or innuendoes likely to provoke a breach of the peace during the electioneering campaigns."
Diplomats, church leaders, the chief of Nigerian police and Africa's richest man Aliko Dangote, were among those who witnessed Thursday's event.
The NPC was formed in 2014 by elder Nigerian statesmen and initiated the peace pledge to support free, fair and credible elections as well as mediate in electoral disputes.
(Reporting by MacDonald Dzirutwe; Editing by Toby Chopra)
