Over the past five days, Boko Haram has seized five towns in Nigeria's northeast, killing hundreds and leaving thousands of residents fleeing for safety as it continues its quest to establish a "caliphate" in the country. The towns captured include Bara in Yobe state, Banki and Bamain Borno state, and Madagali and Gulakwere in Adamawa state. Boko Haram forces were driven from Bama, in Borno state, after intense aerial bombardment by Nigeria's air force Sept. 7. Tension is mounting in Maiduguri, the Borno state capital, amid fears that the insurgents are mounting an offensive on the city. Further territorial gains by Boko Haram could worsen a dire humanitarian situation. Thousands of refugees have sought sanctuary in Maiduguri, and the UN estimates that 9,000 fleeing violence have arrived in Cameroon in the past ten days, with another 2,000 crossing into Niger, which has already taken in 50,000 refugees since May 2013. (The Punch, ThisDayLive, Nigeria; Leadership, Nigeria, via AllAfrica, Sept. 7; The Economist, Sept. 6)