Nigeria's Muhammadu Buhari edges ahead of President Goodluck Jonathan in early election counts, though key states are yet to declare.
The UK's economy grew at a faster pace than initially estimated last year, revised official figures show.
The aunt of Jonas and Hasan Edmonds, two Illinois men charged with conspiring to aid Islamic State, speaks to the BBC about the impact the arrests have had on their family.
The remarkable and beautiful forms sculpted by volcanic eruptions
Inspired by the heroic Ruckus scooter, this concept motorbike aims to conquer a crumbling infrastructure.
When nuclear-powered submarines reach the end of their lives, dismantling them is a complicated and laborious process. Paul Marks investigates.
A much-heralded entrepreneurship revolution is sweeping the continent, but access to high-speed internet remains poor. Is fibre optic cable the answer?
Go-anywhere, survive-anything military transportation can be had for a price - but a desirable new vehicle remains strictly off-limits.
Can't find it? Try the A to Z
Copyright © 2015 BBC. The BBC is not responsible for the content of external sites. Read more.