Editor's note: Reuters provides this background on Tuesday's bomb attack in Yola, Nigeria. 'Suspected Boko Haram militants have carried out attacks in neighboring Chad, Niger and Cameroon in recent weeks, but have not struck northeastern Nigeria since late October when bombings in Yola and Maiduguri left at least 37 people dead.' - Tom
Maiduguri, also called Yerwa by its locals, is the capital and the largest city of Borno State in north-eastern Nigeria. The city sits along the seasonal Ngadda River which disappears into the Firki swamps in the areas around Lake Chad. Maiduguri was founded in 1907 as a military outpost by the British and has since grown rapidly with a population exceeding a million by 2007.