TOPSHOTS A man injured in a suicide blast is transported on a bed at the General Hospital in northeast Nigerian town of Potiskum on January 12, 2015. Four people were killed and 46 injured when two female suicide bombers detonated their explosives outside a mobile phone market in the town on January 11, 2015. Although no one claimed responsibility the attacks bore the hallmark of Boko Haram Islamists who have been increasingly using female suicide bombers in their armed campaign to establish a hardline Islamic state. Potiskum, the commercial hub of Yobe state has been repeatedly attacked by Boko Haram. AFP PHOTO / Aminu ABUBAKAR