A high-ranking traditional leader has been killed in northern Nigeria after his convoy came under attack by suspected Boko Haram militants. Gunmen shot dead the Emir of Gwoza, Shehu Mustapha Idris Timta, in his car. Boko Haram has waged an increasingly bloody insurgency since 2009 to create an Islamic state in Nigeria. Nigeria#039;s President Goodluck Jonathan vowed to wage quot;total warquot; against the group, which has been held more than 200 girls captive since last month. quot;They shot...