He stated this at a news conference on Monday night in Bauchi.
The Independent National Electoral Commission (INEC) on Monday declared Bala Mohammed of the Peoples Democratic Party (PDP) as the winner of the election.
The incumbent governor polled 525,280 votes to defeat his closest contender, Mr Abubakar, who garnered 432,272 votes.
Mr Abubakar alleged that the election was marred with rigging.
“Our preliminary interrogation of INEC e–platforms produced evidence of unprecedented manipulation of the results in total disregard of extant electoral laws and rules,” the APC governorship flag bearer stated.
He added, “It is clear to us that based on what we now know, I am the clear winner of this election. How else can someone explain the results from Toro, Warji, Zaki, Alkaleri and Bauchi local government areas, where violence led to (the) cancellation of results, among others.”
According to him, the APC will consult stakeholders and come up with a position on the election result.
While urging the people to remain calm, Mr Abubakar thanked them for supporting the party and his candidature.