Seventeen people including three Nigerian soldiers have been killed in clashes between the Nigerian army and members of Boko Haram in the northeast.The Nigerian Defense Ministry said in a statement that “altogether three soldiers died” in the battle and 14 members of Boko Haram were killed “after a mop-up of scenes of battle” since May 18. Seven soldiers were also wounded, the defense ministry said, adding that the injured were being treated in a military medical facility. Brigadier General Chris Olukolade, the director of Defense Information, said on Monday that one trooper had gone missing and that the government forces had been engaged in heavy clashes for the last two days. He added that the Nigerian troops also arrested 20 people during the offensive against the Salafist militants. Nigeria has intensified its military campaign against the militants in the northeast to retake the seized territories. The military also carried out airstrikes on militant strongholds in remote parts of Borno State. The campaign has spread to Maiduguri, the Borno State capital, which is also Boko Haram’s traditional home base. On May 18, the Nigerian army imposed a 24-hour curfew in 12 neighborhoods of Maiduguri. According to residents, soldiers closed roads heading out of Maiduguri and blocked supply routes to remote towns. Brigadier General Olukolade said on Sunday that the fight against the militants would continue “as long as it takes” to achieve its main objectives. Nigerian President Goodluck Jonathan has imposed a state of emergency in the states of Borno, Yobe, and Adamawa, saying Boko Haram had captured territory and declared war on the government. On May 7, Boko Haram members launched attacks on military barracks, police stations, and a prison in the town of Bama in northeastern Nigeria, killing 55 people and facilitating the escape of over 100 inmates from the prison. Boko Haram has claimed responsibility for a number of deadly shooting attacks and bombings in various parts of Nigeria since 2009.