Muhammadu Buhari sworn in as President of Nigeria.
The winner of Nigeria's presidential election in March, Muhammadu Buhari, has been sworn in as leader of Africa's most populous country.
Mr. Buhari is the first opposition figure to win a presidential election in Nigeria's 55 years of independence.
He takes over from Goodluck Jonathan, who has urged his successor to unite the country in the face of the threat from Boko Haram militants.
Mr. Buhari, a former military ruler, says he is a convert to democracy.
He defeated Mr Jonathan - who had been in office since 2010 - by 15.4 million votes to 12.9 million.
Watch live as Buhari is sworn in as President.