An armored vehicle used by Boko Haram militants captured by the Nigerian military in Maiduguri, Borno state, late last month. The extremist group appears to be expanding its operations into neighboring countries in an effort to establish an independent Islamic state. EPA/Landov hide caption

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Photos of Luanda, Angola, tell a tale of two cities: sprawling poor neighborhoods and a glitzy waterfront. Saul Loeb/Getty Images; Michael Gottschalk/Getty Images hide caption

toggle caption Saul Loeb/Getty Images; Michael Gottschalk/Getty Images