Nigerian President Muhammadu Buhari, a member of the governing All Progressives Congress (APC) party, has been re-elected for a second four year term. The 76-year-old Buhari defeated his main rival, former Vice President Atiku Abubakar with a margin of around 4 million votes. Buhari has been lauded for his progress against the insurgent group Boko Haram, which has killed more than 10,000 and displaced millions.