Abuja - Nigerian opposition presidential candidate General Muhammadu Buhari called for calm in the country and cautioned against any violence following postponement of elections.
Foreign powers are closely observing the course of elections in Africa's biggest economy and have voiced concerns there could be a repetition of violence that followed 2011 elections when 800 people died.
"Any act of violence can only complicate the security challenges in the country and provide further justification to those who would want to exploit every situation to frustrate the democratic process," Buhari said
Nigeria's electoral commission has postponed elections due on 14 February to 28 March.
The postponement could stoke unrest in opposition strongholds such as the commercial capital, Lagos, and Nigeria's second city, Kano. The opposition has been staunchly against a delay.
The poll will pit incumbent Goodluck Jonathan of the PDP against former military ruler Buhari of the All Progressives Congress (APC) in what is likely to be the most hotly contested election since the end of military rule in 1999.
Buhari said 28 March must now be sacrosanct.
"I wish to state strongly that our party will not tolerate any further interference in the elections."