Two children walk in an empty street as they make their way home in the city of Maiduguri, Borno State May 19, 2013, an area where President Goodluck Jonathan has declared a state of emergency. In their biggest offensive since the insurgency began in 2009, Nigerian forces are trying to chase well-armed militants out of territory they control in remote semi-deserts around Lake Chad, along the borders with Cameroon, Chad and Niger. They have also launched a crackdown on them in northeastern cities such as Maiduguri, where the sect has powerful cells. REUTERS/Afolabi Sotunde (NIGERIA - Tags: POLITICS CIVIL UNREST)