The presidential candidate of the Peoples Democratic Party, Atiku Abubakar, was conspicuously absent at the signing of a peace pact for 2019 presidential candidates in Abuja.
President Muhammadu Buhari arrived at the International Conference Centre to join other candidates in signing the peace agreement, which was drafted by the National Peace Committee.
It was not immediately clear why Atiku, the major challenger to Buhari, did not turn up at the event.
But spokespersons for the PDP flagbearer said that they were not aware of the event, which began at 3:00 p.m., and promised to make urgent findings and revert.
Abdulsalam Abubakar, a former Nigerian military ruler, is the convener of the committee and the event.
A similar pact was signed by presidential candidates in 2015 and the committee was widely deemed crucial to the peaceful outcome of that contentious election.