The presidential poll on Feb. 14 has already triggered deadly skirmishes and the International Criminal Court (ICC) has said on Monday that Nigeria's leaders must not whip up violence around the presidential polls.
President Goodluck Jonathan, a Christian from the south, faces Muhammadu Buhari, a northern Muslim, in an atmosphere of heightened regional, ethnic and sectarian tensions that many fear could boil over into widespread violence.
The election is expected to be the most closely contested since the end of military rule in 1999. "Experience has shown that if electoral competition, goes astray, it can give rise to violence and... even trigger the commission of mass crimes," the ICC's Fatou Bensouda said. "Any person who incites or engages in acts of violence including by ordering, requesting, encouraging... crimes within ICC's jurisdiction is liable to prosecution," she said in a statement.
Some 800 people were killed and 65,000 displaced in three days of rioting in the largely Muslim north after Buhari lost to Jonathan in 2011.
The ICC has been looking into possible war crimes in Nigeria since 2010, but few believe it would be keen to take on another powerful politician after being forced to drop charges related to 2007 electoral violence against Kenyan President Uhuru Kenyatta in December.
Supporters of Buhari's All Progressives Congress (APC) and the ruling People's Democratic Party (PDP) have already clashed in street battles that have killed several people.
An online Newspaper last year reported that one PDP governor in a video urged his supporters to crush APC "cockroaches", in a chilling echo of the Rwandan genocide.
The APC has also threatened to set up a parallel government if the election is rigged.
Islamist militant group Boko Haram, which regards democracy as un-Islamic, may disrupt the voting for both sides in the areas of the northeast where it operates.
Add your comments here.