Elections in parts of Nigeria have been extended until
Sunday after delays and a number of attacks.
The delays were "not widespread" but were still "a
matter of concern", an election official told the BBC.

Technical problems with new biometric cards slowed
down voter registration, even affecting President
Goodluck Jonathan.

More than 20 people have reportedly been killed in
various attacks by unknown gunmen.
Mr Jonathan is facing a strong challenge from
Muhammadu Buhari.

The election is said to be the most closely fought since
independence.

It was postponed from mid-February to allow the army
time to recapture territory from the Islamist militants
of Boko Haram.

The two main candidates had pledged to prevent
violence during and in the aftermath of the elections.
But several hours after voting started, reports came in
of violent incidents at polling stations in which at least
24 were reported to have been killed.

Thousands of Nigerians turned out to vote, despite
threats from Boko Haram to disrupt the poll.

"We have suffered enough, fled our homes after many
attacks," said Roda Umar, a housewife from the former
militant headquarters of Gwoza. "I'm ready to endure
the pain to vote."

'Slow progress'

Voters are also electing members of the house of
representatives and the senate.
According to the Transitional Monitoring Group (TMG),
the largest body observing the elections, voting had
started in 75% of polling stations, while 92% had the
materials they need to start the process.

Voters need to register using biometric cards with their
fingerprints before they can cast their vote.
However, there have been problems with the card
readers at many polling stations.

The Independent National Electoral Commission (Inec)
said the accreditation process had "gone on well in
several places", but was "slow" or had "not commenced
at all" in others.

President Jonathan tried for some 50 minutes to
register in his home village of Otuoke, before coming
back a second time. When the electronic registration
failed again, he had to be accredited manually and did
eventually cast his ballot paper.

Problems were also reported from the north's biggest
city of Kano, where thousands of voters waited for
election officials and voting materials to arrive.

"No-one has shown up from Inec... This is a deliberate
attempt to sabotage the elections," Ismail Omar, a 65-
year-old builder, told AFP news agency.

Gen Buhari did not have any problems registering in his
hometown, Daura.

After voting, he told the BBC the process was "in order but I have been watching activities in other states, which is disappointing, but overall it's on course".