Nigeria's electoral commission on Saturday said polling in the country's presidential and parliamentary election had been suspended in some places because of glitches with new voter ID card readers.
The Independent National Electoral Commission said there had been "challenges" with the technology in "many" places, without specifying a number, forcing accreditation to be suspended.
"In polling units where accreditation was suspended to the following day in accordance with the existing guidelines, arrangement will be made for voters to vote tomorrow (Sunday)," information commissioner Chris Yimoga told reporters in Abuja.
Voters have reported long delays with the new handheld devices that "read" biometric data such as fingerprints on the cards to authenticate a voter's identity and cut electoral fraud.
The most high-profile victim was President Goodluck Jonathan, who was forced to abandon his accreditation in his home town of Otuoke when the device repeatedly failed to recognise his details.
He was then accredited by hand and later voted, he said, for himself in the presidential vote and his ruling Peoples Democratic Party (PDP) in parliamentary polls.
Jonathan said people should "sympathise with INEC", adding: "INEC introduced the card readers to ensure we get credible elections. We should bear with them...
"INEC has to talk about their functions. I took the manual option. I am aware that INEC has directed its resident electoral commissioners to use manual option when card readers fail.
"As head of state, I don't blame anybody," he said but admitted: "I think the problem is national."
Jonathan's PDP repeatedly expressed concern about the level of distribution of new voter ID cards and the use of the "untested" readers during the election campaign. The main opposition All Progressives Congress (APC) backed the system.
INEC's Yimoga said although accreditation had "gone well in several places... (it) has been slow in many places and has not commenced in others".
Election guidelines already provided for accreditation to be postponed to the following day if card readers did not work and could not be replaced.
But he added that a revision was made because of "the scale of the challenge we have observed", allowing both a 24-hour delay and the use of manual checking.
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