Voting in Nigeria's general election has been extended to tomorrow in 300 out of 150,000 polling stations.
The electoral commission decided to extend it due to technical glitches which marred polling nationwide.
Hand-held card readers which scan voter's biometric data malfunctioned or failed at various polling stations across Africa's most populous country.
In 109 polling stations cards were not read at all.
In another 100 stations where there were issues with biometric data, while card readers in other areas had battery problems.
The commission had earlier said that given the widespread malfunctioning of card readers, electoral officers had been empowered to manually check voter cards against a hard copy of the electoral roll.
During the election campaign, President Goodluck Jonathan's Peoples Democratic Party (PDP) repeatedly criticised the technology, which is designed to "read" fingerprints and other personal data in 10 seconds.
The main opposition All Progressives Congress (APC) backed the use of the devices as a way of combating widespread vote-rigging in previous elections.
Elsewhere, Suspected Boko Haram gunmen have beheaded 23 people and set fire to homes in Buratai, northeast Nigeria, last night.
"There was an attack on Buratai late Friday by gunmen suspected to be insurgents.... They beheaded 23 people and set homes on fire," said Mohammed Adamu, who represents the town some 200km from Borno's capital Maiduguri.
A nurse at the nearest major hospital, in Biu, said the 32 injured who were receiving care also reported that many were decapitated during the attack.
Meanwhile, a prompt start was reported in the Borno and Adamawa state capitals Maiduguri and Yola in the north, where voting was taking place in and around camps for people made homeless by the Boko Haram conflict.
But there were delays in President Goodluck Jonathan's home town of Otuoke, in southern Bayelsa state, and in the northern town of Daura, Katsina state, where challenger Muhammadu Buhari lives.
In the capital Abuja, the deadline for registration was extended indefinitely at the Nyanya Jum'at Mosque polling station but the electoral commission said this was within the rules.
