BBC News with Jerry Smit

The incumbent Goodluck Jonathan has been officially declared the winner in Nigeria’s presidential election. However, Mr Jonathan has had to

appeal for

calm as violence

erupt

ed across parts of northern Nigeria in response to his victory. From Abuja, here’s Caroline Duffield.

Goodluck Jonathan received nearly 23 million votes in the presidential election, while his rival General Muhammadu Buhari got just over 12 million. But minutes before the declaration, Goodluck Jonathan was appealing for calm. Angry youths, supporters of the defeated Mr Buhari, have torched homes, churches and cars, and set up burning barricades in towns and cities across northern Nigeria. So far, General Buhari’s party, the Congress for Progressive Change, have steadily refused to condemn the violence or to call for calm.

A ship chartered by an aid agency has evacuated about 1,000 people from the Libyan city of Misurata, which is under

constant

siege by Colonel Gaddafi’s forces. The International Organisation for Migration said thousands more were waiting to be rescued in what it described as an increasingly

perilous

situation.

An international credit rating agency has downgraded its

assessment

of the long-term outlook for government finances in the United States from ‘stable’ to ‘negative’. The US Treasury responded by saying the agency had