(The Root) — The signs are ominous, and strangely familiar: communal warfare raging in the politically volatile Muslim Northern regions, with supporters of the ruling party stabbed, hacked or shot; churches, mosques and homes burned; and hundreds believed dead and tens of thousands more displaced. That’s the scene so far in parts of Nigeria, Africa’s most populous nation, following its latest round of presidential elections. Gubernatorial elections in at least three Northern states this week were postponed because of the violence. The incumbent, President Goodluck Jonathan, of the ruling People’s Democratic Party, has appealed for calm after being declared the winner April 18 with 57 percent of the vote — thus avoiding an expected second round of balloting with his main rival, former Gen. Muhammadu Buhari, who received 31 percent. Buhari is a Fulani from the predominantly Muslim North; Jonathan is an Ijaw from the predominantly Christian South.