Millions turn out to vote in Nigerian presidential elections

Tens of millions of Nigerians have come out to vote in the country's presidential election.

Incumbent Goodluck Jonathan cast his ballot in his home state of Bayelsa in the oil-rich Niger Delta. His main challenge for the presidency is expected to come from a former military leader, Muhammadu Buhari.

The vote is being seen as a major break with the past, and observers say the poll could be Nigeria's first credible election for decades.

Caroline Duffield reports.