UN chief Ban Ki-moon begins a visit to Nigeria at the weekend to commemorate a deadly attack on the global body by Boko Haram militants and meet the country's new leader.
Two suicide attacks in northeast Nigeria killed at least 38 people, less than six weeks from elections, as the leader of Boko Haram vowed to disrupt the vote.
Suspected Boko Haram militants kidnapped the wife of a senior Cameroonian minister and a traditional leader in attacks in the far north of the country that left at least six dead.
A military court in Cameroon has handed down prison sentences of up to 20 years to 14 Boko Haram members, the country's state broadcaster Crtv reported.
Nigerian authorities have arrested one suspect, and killed another, after a bomb claimed 21 lives in a shopping centre in the capital Abuja, a city gripped by fear of attacks by Boko Haram Islamists.