Vote counting is underway in Nigeria's tightest presidential election since military rule ended in 1999. Turnout appeared to be high, with many young, first-time voters arriving before dawn to cast their ballots.<br />'' <br />'' Saturday's voting was marred by long delays at polling stations, as well as scattered reports of ballot box snatching and attacks by armed men.<br />'' <br />'' And some parties have raised alarm over allegations of irregularities, which could lead to a disputed outcome.<br />'' <br />'' The elections are the biggest democratic exercise in Africa, with 87 million people eligible to vote. Politics has been dominated by two parties – the ruling APC and the PDP – since the restoration of multi-party democracy 24 years ago.<br />'' <br />'' But this time, there is also a strong challenge from a third-party candidate in the race to succeed President Muhammadu Buhari – from the Labour Party's Peter Obi, who is backed by many young people.<br />'' <br />'' Tens of thousands of polling stations are counting the results, which will be collated and sent to the electoral headquarters in the capital Abuja.<br />''The final result is not expected until at least Tuesday.