Incumbent president Goodluck Jonathan is struggling to cast his vote in a tight election contest underway in Nigeria, BBC has reported.

The leader of the governing People's Democratic Party cannot be verified  by the machine, which is a requirement for his vote.

 "Pres Jonathan still waiting to be verified as card reader seems to be malfunctioning #nigeriadecides2015 @BBCAfrica" Peter Okwoche tweeted.

He had gone to Otuoke polling station with the support of his wife Patience Jonathan and has been waiting to go through the verification process before casting his vote.

The malfunctioning of the verification machine appears to be widespread.

"Only one in five successes so far on reading thumb print here in Nyanya, outside Abuja. Have to compare photo on voter list to face where machine fails," the BBC reported.

Jonathan is seeking a second term in an election which is being contested by 13 others.

However, the biggest contender is leader of the All Progressive Congress (APC), Muhammadu Buhari, who has already been accredited and ready to vote in the Daura town.

"I like the integrity of the system... If people are allowed to vote then rigging will be virtually impossible under the system." he told reporters.

Meanwhile hours after reports filtered through about the recapture of the Boko Haram headquarters by government forces, there has been reports of bomb blast in the morning of the election.

"Nigeria's privately owned Channels Television is reporting that there has been a bomb blast at a polling station in Enugu state, in south-eastern Nigeria," the BBC said.

It is not clear yet if there were any casualties.