Voting began in Nigeria's general election on Saturday but delays were reported countrywide because of technical problems in accrediting electors.
There was a mixed picture across the country, with people at some polling units reporting no problems in casting their ballot from 1230 GMT but others still waiting for their identities to be checked.
"Actual voting started at 1:30 pm (1230 GMT)," stockbroker Foluso Ogunleye told AFP from the Ikeja district of Lagos, the country's financial centre.
"Some people in the queue have voted. Everything is orderly here. There are two polling stations in this area and there are more than 500 people waiting to vote."
A prompt start was also 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.
The delay was attributed to problems with new technology to "read" biometric voter identity cards, which in some cases forced election officials to return to the old system of registration by hand.